BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CMSA - ECPv6.16.3//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:CMSA
X-ORIGINAL-URL:https://cmsa.fas.harvard.edu
X-WR-CALDESC:Events for CMSA
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20230312T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20231105T060000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20240310T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20241103T060000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20250309T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20251102T060000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20260308T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20261101T060000
END:STANDARD
END:VTIMEZONE
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20230312T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20231105T060000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20240310T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20241103T060000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
DTSTART:20250309T070000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
DTSTART:20251102T060000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250325T160000
DTEND;TZID=America/New_York:20250325T170000
DTSTAMP:20260614T000527
CREATED:20250128T213506Z
LAST-MODIFIED:20250326T194012Z
UID:10003701-1742918400-1742922000@cmsa.fas.harvard.edu
SUMMARY:Unstable Fluids in Expanding Cosmologies
DESCRIPTION:General Relativity Seminar \nSpeaker: Elliot Marshal\, School of Mathematics at Monash University \nTitle: Unstable Fluids in Expanding Cosmologies \nAbstract: The FLRW solution is the simplest cosmological model in general relativity\, describing a fluid-filled\, spatially homogeneous universe. While there is extensive literature in the physics community on cosmological models with a linear equation of state \, rigorous stability results have\, until recently\, been limited to FLRW models with accelerated expansion and small sound speeds. In this talk\, I will discuss numerical work on two types of instabilities which can occur in non-linearly perturbed FLRW models outside of this regime. The first concerns a longstanding conjecture of Alan Rendall on FLRW models with positive cosmological constant and super-radiative (K>1/3) equations of state. Our numerical work\, in collaboration with F. Beyer and T.A. Oliynyk\, supports Rendall’s conjecture and highlights the underlying mechanism for the instability. In the second case\, I will discuss evidence that perturbations of slowly expanding (decelerated) FLRW models generically form shocks in finite time. This contrasts with known results for accelerated models where shock formation is suppressed for suitably small perturbations.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-32525/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-3.25.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250226T140000
DTEND;TZID=America/New_York:20250226T150000
DTSTAMP:20260614T000527
CREATED:20250124T154400Z
LAST-MODIFIED:20250623T124501Z
UID:10003663-1740578400-1740582000@cmsa.fas.harvard.edu
SUMMARY:Datasets for Math: From AIMO Competitions to Math Copilots for Research
DESCRIPTION:  \nNew Technologies in Mathematics Seminar \nSpeaker: Simon Frieder\, Oxford \nTitle: Datasets for Math: From AIMO Competitions to Math Copilots for Research \nAbstract: This talk begins with a brief exposition of the AI Mathematical Olympiad (AIMO) on Kaggle\, now in its second iteration\, outlining datasets and models available to contestants. Taking a broader perspective\, I then examine 1) the overarching issues the current datasets suffer from—such as binary evaluation or constrained sets of use cases— and 2) the trajectory they set for competition-style mathematical problem-solving\, which is different from mathematical research practice. I argue for a fundamental shift in dataset structure and composition\, both for training and evaluation\, and introduce the idea of mapping mathematical workflows to data\, a key example underscoring the need for this shift. I touch upon new thinking LLMs and their role in redefining LLM math evaluation\, highlighting their implications for dataset design. Finally\, I propose general improvements to the current state of mathematical datasets\, including mathematical adaptations of dataset documentation (e.g.\, datasheets). \n 
URL:https://cmsa.fas.harvard.edu/event/newtech_22625/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/1740494700974-e6086db9-08ab-4681-9ecd-580092fe27b62025-1_1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250220T100000
DTEND;TZID=America/New_York:20250220T110000
DTSTAMP:20260614T000527
CREATED:20250128T171842Z
LAST-MODIFIED:20250218T155455Z
UID:10003678-1740045600-1740049200@cmsa.fas.harvard.edu
SUMMARY:The geometry of pure spinor superfield formalism 
DESCRIPTION:Mathematical Physics and Algebraic Geometry Seminar \nSpeaker: Simone Noja (Heidelberg University) \nTitle: The geometry of pure spinor superfield formalism \nAbstract: In this talk I will present a mathematical perspective on the pure spinor superfield formalism. In particular\, I will discuss how field multiplets in supersymmetric theories can be constructed mathematically from geometric data associated with certain algebraic varieties—namely\, the nilpotence variety of the (super)symmetry algebra of the theory. After discussing key examples\, I will\, time permitting\, outline a possible generalization of the formalism within the framework of derived geometry.
URL:https://cmsa.fas.harvard.edu/event/mathphys_22025/
LOCATION:Virtual
CATEGORIES:Mathematical Physics and Algebraic Geometry
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Mathematical-Physics-and-Algebraic-Geometry-2.20.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250218T110000
DTEND;TZID=America/New_York:20250218T120000
DTSTAMP:20260614T000527
CREATED:20240903T191953Z
LAST-MODIFIED:20250219T144101Z
UID:10003426-1739876400-1739880000@cmsa.fas.harvard.edu
SUMMARY:General Relativity Seminar
DESCRIPTION:General Relativity Seminar \nSpeaker: Maximilian Ofner\, University of Vienna \nTitle: Stability and Instability of Relativistic Fluids in Slowly Expanding Spacetimes \nAbstract: Homogeneous and isotropic solutions to the relativistic Euler equations are known to be unstable on a Minkowski background. However\, for FLRW models with a fast expansion rate\, relativistic fluids stabilize. This scenario suggests a transition between stable and unstable behavior\, somewhere along a family of spacetimes parametrized by their expansion rate. In this talk we will discuss this phase transition for various equations of state\, focusing on the regime of linear and decelerated expansion. This is based on recent analytical results\, complemented by numerical analysis.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-21825/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-2.18.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250212T140000
DTEND;TZID=America/New_York:20250212T150000
DTSTAMP:20260614T000527
CREATED:20250123T194306Z
LAST-MODIFIED:20250228T212617Z
UID:10003661-1739368800-1739372400@cmsa.fas.harvard.edu
SUMMARY:Discovering Data Structures: Nearest Neighbor Search and Beyond
DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Omar Salemohamed\, Mila \nTitle: Discovering Data Structures: Nearest Neighbor Search and Beyond \nAbstract: As neural networks learn increasingly sophisticated tasks—from image recognition to mastering the game of Go—we ask: can deep learning discover data structures entirely from scratch? We introduce a general framework for data structure discovery\, which adapts to the underlying data distribution and provides fine-grained control over query and space complexity. For nearest neighbor (NN) search\, our model (re)discovers classic algorithms like binary search in one dimension and learns structures reminiscent of k-d trees and locality-sensitive hashing in higher dimensions. Additionally\, the model learns useful representations of high-dimensional data such as images and exploits them to design effective data structures. Beyond NN search\, we believe the framework could be a powerful tool for data structure discovery for other problems and adapt our framework to the problem of estimating frequencies over a data stream. To encourage future work in this direction\, we conclude with a discussion on some of the opportunities and remaining challenges of learning data structures end-to-end.
URL:https://cmsa.fas.harvard.edu/event/newtech_21225/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-2.12.2025.docx-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250210T110000
DTEND;TZID=America/New_York:20250210T120000
DTSTAMP:20260614T000527
CREATED:20250128T192122Z
LAST-MODIFIED:20250203T191001Z
UID:10003687-1739185200-1739188800@cmsa.fas.harvard.edu
SUMMARY:On 5d conformal matter
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Mario De Marco (UL Brussels) \nTitle: On 5d conformal matter \nAbstract: SCFTs with 8 supercharges lie at the sweet spot of the classification program of susy scale-invariant theories: with this amount of susy\, the classification is in principle achievable\, despite being non-trivial. In this talk\, I will present the geometric approach to the classification of 5d SCFTs\, based on geometric engineering on non-compact Calabi-Yau manifolds. The strategy is to imagine a 5d SCFT as a non-Lagrangian generalization of a quiver\, and to build this generalised quiver by gauging together indecomposable blocks\, called  “5d conformal matter theories”. In this talk\, I will start with a recap of the geometric construction of [2311.04984]. I will then present some forthcoming results\, concerning the (p\,q) web realization of 5d conformal matter theories\, their reduction to 4d\, their magnetic quiver\, and the discovery of exotic “trifundamental” and “quadrifundamental” 5d indecomposable blocks (with flavor group at least SO(4k+2)^3 or SO(4k)^4). \nIn collaboration with M. Del Zotto\, M. Graffeo\, J. Grimminger\, and A. Sangiovanni. \n 
URL:https://cmsa.fas.harvard.edu/event/qft_21025/
LOCATION:Virtual
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-2.10.25-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250207T140000
DTEND;TZID=America/New_York:20250207T154500
DTSTAMP:20260614T000527
CREATED:20250127T151529Z
LAST-MODIFIED:20250127T155730Z
UID:10003673-1738936800-1738943100@cmsa.fas.harvard.edu
SUMMARY:Is every knot isotopic to the unknot?
DESCRIPTION:Freedman CMSA Seminar \n*via Zoom* \nSpeaker: Sergey Melikhov\, Steklov Math Institute \nTitle: Is every knot isotopic to the unknot? \nAbstract: The following problem was stated by D. Rolfsen in his 1974 paper; according to R. Daverman it was being discussed since the mid-60s. Is every knot in $S^3$ isotopic (=homotopic through embeddings) to a PL knot — or\, equivalently\, to the unknot? In particular\, is the Bing sling isotopic to a PL knot? We show that the Bing sling $B$ is not isotopic to any PL knot by an isotopy which extends to an isotopy of any 2-component link obtained from $B$ by adding a disjoint component $Q$ such that $lk(B\,Q)=1$. Moreover\, the assertion remains true if the additional component is allowed to self-intersect\, and even to get replaced by a new one at any time instant $t$\, as long as it remains disjoint from the original component $K_t$ and represents the same conjugacy class as the old one in $G/[G’\,G”]$\, where $G=\pi_1(S^3\setminus K_t)$. The are examples showing that the latter result cannot be improved in certain ways. I plan to present a sketch of the proof\, modulo some ingredients. The details can be found in arXiv:2406.09365 and the main ingredients in arXiv:2406.09331 and arXiv:math/0312007v3. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_2725/
LOCATION:Virtual
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-2.7.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250206T100000
DTEND;TZID=America/New_York:20250206T110000
DTSTAMP:20260614T000527
CREATED:20241017T135403Z
LAST-MODIFIED:20250131T173042Z
UID:10003594-1738836000-1738839600@cmsa.fas.harvard.edu
SUMMARY:Quantum algebras and R-matrices from the equivariant affine Grassmannians
DESCRIPTION:Mathematical Physics and Algebraic Geometry Seminar \nSpeaker: Wenjun Niu\, Perimeter Institute \nTitle: Quantum algebras and R-matrices from the equivariant affine Grassmannians \nAbstract: In this talk\, I will explain my joint work with R. Abedin\, in which we construct\, for each Lie algebra g\, a Hopf algebra and a spectral R-matrix satisfying quantum Yang-Baxter equation. This Hopf algebra is a quantization of the Lie bi-algebra structure on T^*g[t] defined by Yang’s r-matrix\, and therefore we call it the Yangian of T^*g. The construction is based on the category of coherent sheaves on the equivariant affine Grassmannian associated to the formal group of g\, and is motivated by the study of the category of line defects in a 4 dimensional holomorphic-topological field theory. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/mathphys_2625/
LOCATION:Virtual
CATEGORIES:Mathematical Physics and Algebraic Geometry
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Mathematical-Physics-and-Algebraic-Geometry-2.6.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250204T110000
DTEND;TZID=America/New_York:20250204T120000
DTSTAMP:20260614T000527
CREATED:20240903T192049Z
LAST-MODIFIED:20250130T190257Z
UID:10003428-1738666800-1738670400@cmsa.fas.harvard.edu
SUMMARY:The mass angular momentum inequality
DESCRIPTION:General Relativity Seminar \nSpeaker: Gilbert Weinstein\, Ariel University \nTitle: The mass angular momentum inequality \nAbstract: We show that either there is a counterexample to black hole uniqueness\, in the form of a regular axisymmetric stationary vacuum spacetime with an asymptotically flat end and multiple degenerate horizons which is ‘ADM stable’\, or the following statement holds. Complete\, simply connected\, maximal initial data sets for the Einstein equations with multiple ends that are either asymptotically flat or asymptotically cylindrical\, admit an ADM mass lower bound given by the square root of total angular momentum\, under the assumption of nonnegative energy density and axisymmetry. Moreover\, equality is achieved bound only for a constant time slice of an extreme Kerr spacetime. The proof is based on a novel flow of singular harmonic maps with hyperbolic plane target\, under which the renormalized harmonic energy is monotonically nonincreasing. Relevant properties of the flow are achieved through a refined asymptotic analysis of solutions to the linearized harmonic map equations.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-2425/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-2.4.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241219T100000
DTEND;TZID=America/New_York:20241219T110000
DTSTAMP:20260614T000527
CREATED:20241203T214207Z
LAST-MODIFIED:20241219T193235Z
UID:10003600-1734602400-1734606000@cmsa.fas.harvard.edu
SUMMARY:Tyurin degenerations\, Relative Lagrangian foliations and categorification of DT invariants
DESCRIPTION:Mathematical Physics and Algebraic Geometry Seminar \nSpeaker: Artan Sheshmani (BIMSA) \nTitle: Tyurin degenerations\, Relative Lagrangian foliations and categorification of DT invariants \nAbstract: We discuss construction of a derived Lagrangian intersection theory of moduli spaces of perfect complexes\, with support on divisors on compact Calabi-Yau threefolds. Our goal is to compute deformation invariants associated to a fixed linear system of divisors in CY3. We apply a Tyurin degeneration of the CY3 into a normal-crossing singular variety composed of Fano threefolds meeting along their anti-canonical divisor. We show that the moduli space over the Fano 4 fold given by total space of degeneration family satisfies a relative Lagrangian foliation structure which leads to realizing the moduli space as derived critical locus of a global (-1)-shifted potential function. We construct a flat Gauss-Manin connection to relate the periodic cyclic homology induced by matrix factorization category of such function to the derived Lagrangian intersection of the corresponding “Fano moduli spaces”. The later provides one with categorification of DT invariants over the special fiber (of degenerating family). The alternating sum of dimensions of the categorical DT invariants of the special fiber induces numerical DT invariants. If there is time\, we show how in terms of “non-derived” virtual intersection theory\, these numerical DT invariants relate to counts of D4-D2-D0 branes which are expected to have modularity property by the S-duality conjecture. This talk is based on joint work with Ludmil Katzarkov\, Maxim Kontsevich\, recent work with Jacob Krykzca\, and former work with Vladimir Baranovsky. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/mathphys_121924/
LOCATION:Virtual
CATEGORIES:Mathematical Physics and Algebraic Geometry
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Mathematical-Physics-and-Algebraic-Geometry-12.19.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241206T160000
DTEND;TZID=America/New_York:20241206T170000
DTSTAMP:20260614T000527
CREATED:20240923T164849Z
LAST-MODIFIED:20241202T185723Z
UID:10003603-1733500800-1733504400@cmsa.fas.harvard.edu
SUMMARY:A simple model for universal quantum computation
DESCRIPTION:Freedman CMSA Seminar \nSpeaker: Michael Freedman \nTitle: A simple model for universal quantum computation \nAbstract: I’ll present joint (unpublished) work with Charlie Marcus on a surprisingly simple – and potentially practical (?)– model for universal quantum computation whose only quantum primitive is the ability to measure a pair of adjacent electrons into either singlet (spin=0) or triplet (spin=1) sectors according to the Born rule. The electrons are located on quantum dots arranged in a triangular lattice whose edges are tiny strips of s-wave superconductor. \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_12624/
LOCATION:Virtual
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-12.06.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241120T100000
DTEND;TZID=America/New_York:20241120T230000
DTSTAMP:20260614T000527
CREATED:20241017T153402Z
LAST-MODIFIED:20241115T183929Z
UID:10003614-1732096800-1732143600@cmsa.fas.harvard.edu
SUMMARY:Thinking Like Transformers - A Practical Session
DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Gail Weiss\, EPFL \nTitle: Thinking Like Transformers – A Practical Session \nAbstract: With the help of the RASP programming language\, we can better imagine how transformers—the powerful attention based sequence processing architecture—solve certain tasks. Some tasks\, such as simply repeating or reversing an input sequence\, have reasonably straightforward solutions\, but many others are more difficult. To unlock a fuller intuition of what can and cannot be achieved with transformers\, we must understand not just the RASP operations but also how to use them effectively.\nIn this session\, I would like to discuss some useful tricks with you in more detail. How is the powerful selector_width operation yielded from the true RASP operations? How can a fixed-depth RASP program perform arbitrary length long-addition\, despite the equally large number of potential carry operations such a computation entails? How might a transformer perform in-context reasoning? And are any of these solutions reasonable\, i.e.\, realisable in practice? I will begin with a brief introduction of the base RASP operations to ground our discussion\, and then walk us through several interesting task solutions. Following this\, and armed with this deeper intuition of how transformers solve several tasks\, we will conclude with a discussion of what this implies for how knowledge and computations must spread out in transformer layers and embeddings in practice.
URL:https://cmsa.fas.harvard.edu/event/newtech_112024/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-11.20.24.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241115T143000
DTEND;TZID=America/New_York:20241115T173000
DTSTAMP:20260614T000527
CREATED:20240923T164810Z
LAST-MODIFIED:20241112T153736Z
UID:10003602-1731681000-1731691800@cmsa.fas.harvard.edu
SUMMARY:Freedman CMSA Seminar
DESCRIPTION:Freedman CMSA Seminar \n*Note: via Zoom only* \n  \n2:00-3:30 pm ET \nSpeaker: Michael Freedman\, Harvard CMSA \nTitle: Some questions and theorems about closed 3 manifolds embedded in S^4 \nAbstract: Much is unknown about smooth embeddings of 3-manifolds in S^4; the Schoenflies problem  (Is there only one smoothly embedded 3-sphere in S^4 up to isotopy?) is the best-known example. There has long been a hope that 3-manifold reasoning applied to level-sets will be helpful.  I’ll mention some successes and failures of this method and revisit a classical theorem of Hantzsche in this light. (Hantzsche: If a 3-manifold embeds in S^4 its linking form is hyperbolic.) \n  \n3:30-4:00 pm ET \nBreak/Discussion \n  \n4:00-5:30 pm ET \nSpeaker: Slava Krushkal\, University of Virginia \nTitle: A higher order torsion linking form for 3-manifolds \nAbstract: This talk is based on a joint work with Mike Freedman defining a triple linking form for rational homology spheres\, assuming that the classical torsion linking pairing of three classes pairwise vanishes. I will discuss its vanishing for 3-manifolds in S^4\, and its relation to the Matsumoto triple intersection form on 4-manifolds. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_11824/
LOCATION:Virtual
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-11.15.2024.docx-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241113T100000
DTEND;TZID=America/New_York:20241113T230000
DTSTAMP:20260614T000527
CREATED:20241017T141250Z
LAST-MODIFIED:20241115T175125Z
UID:10003613-1731492000-1731538800@cmsa.fas.harvard.edu
SUMMARY:Frontier of Formal Theorem Proving with Large Language Models: Insights from the DeepSeek-Prover Series
DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Huajian Xin\, DeepSeek \nTitle: Frontier of Formal Theorem Proving with Large Language Models: Insights from the DeepSeek-Prover Series \nAbstract: Recent advances in large language models have markedly influenced mathematical reasoning and automated theorem proving within artificial intelligence. Yet\, despite their success in natural language tasks\, these models face notable obstacles in formal theorem proving environments such as Lean and Isabelle\, where exacting derivations must adhere to strict formal specifications. Even state-of-the-art models encounter difficulty generating accurate and complex formal proofs\, revealing the unique blend of mathematical rigor required in this domain. In the DeepSeek-Prover series (V1 and V1.5)\, we have explored specialized methodologies aimed at addressing these challenges. This talk will delve into three foundational areas: the synthesis of training data through autoformalization\, reinforcement learning that utilizes feedback from proof assistants\, and test-time optimization using Monte Carlo tree search. I will also provide insights into current model capabilities\, persistent challenges\, and the future potential of large language models in automated theorem proving.
URL:https://cmsa.fas.harvard.edu/event/newtech_111324/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-11.13.24.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241108T100000
DTEND;TZID=America/New_York:20241108T113000
DTSTAMP:20260614T000527
CREATED:20240907T194143Z
LAST-MODIFIED:20241104T181059Z
UID:10003470-1731060000-1731065400@cmsa.fas.harvard.edu
SUMMARY:Representations of minimal W-algebras: unitarity and modular invariance
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Victor Kac (MIT) \nTitle: Representations of minimal W-algebras: unitarity and modular invariance \nAbstract: The minimal W-algebras\, obtained by quantum Hamiltonian reduction from affina vertex algebras\, form the most interesting class of vertex algebras\, which includes all superconformal algebras: Virasoro\, Neveu-Scharz\, N=2\, 3\, 4\, and big N=4. I will explain a unified classification of their unitary representations\, and their character formulas. For N=0\, 1\, and 2 these vertex algebras are modular invariant (meaning that tr q^L_0-c/24 is a modular function). However for all other minimal W-algebra modular invariance fails\, and one needs the “modification” of characters to restore modular invariance. Unfortunately the representation-theoretical or physical meaning of the modification is not known (at least to me).
URL:https://cmsa.fas.harvard.edu/event/qm_11824/
LOCATION:Virtual
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-11.8.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241029T110000
DTEND;TZID=America/New_York:20241029T120000
DTSTAMP:20260614T000527
CREATED:20240903T183326Z
LAST-MODIFIED:20241026T192248Z
UID:10003425-1730199600-1730203200@cmsa.fas.harvard.edu
SUMMARY:Formation of Trapped Surfaces in Geodesic Foliation
DESCRIPTION:General Relativity Seminar \nSpeaker: Xuantao Chen\, Johns Hopkins University \nTitle: Formation of Trapped Surfaces in Geodesic Foliation \nAbstract: We reprove the formation of trapped surfaces for the Einstein vacuum equation using the incoming geodesic foliation. All previous results\, starting with the seminal work of Christodoulou\, make use of the double null foliation. In the new proof\, all Ricci coefficients are estimated by transport equations in the incoming null direction\, and the incoming initial data is only used in the curvature (energy) estimates. The result is based on a version of the non-integrable PT frame\, which was introduced in the proof of Kerr stability with small angular momentum. \n 
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-102224/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-10.29.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241025T143000
DTEND;TZID=America/New_York:20241025T173000
DTSTAMP:20260614T000527
CREATED:20240907T191539Z
LAST-MODIFIED:20241010T152044Z
UID:10003466-1729866600-1729877400@cmsa.fas.harvard.edu
SUMMARY:Freedman CMSA Seminar
DESCRIPTION:Freedman CMSA Seminar \n*Note: via Zoom only* \n2:00-3:30 pm ET \nSpeaker: Matt Hastings\, Microsoft Quantum Program \nTitle: Invertible Phases of Matter and Quantum Cellular Automata: Dimensions One to Three \nAbstract: A Quantum Cellular Automaton (QCA) is a *-automorphism of the algebra of local operators. While local quantum circuits provide one example of QCA\, we are most interested in nontrivial QCA which are those which cannot be written as conjugation by a local quantum circuit. For systems in one and two spatial dimensions\, all nontrivial QCA are shifts (i.e.\, translations by some amount)\, up to conjugation by a quantum circuit\, but in three and higher dimensions\, other examples are known. I’ll explain the relation between QCA and a certain “boundary algebra” of operators in one lower spatial dimension\, and also the relation to invertible phases of matter on the boundary\, and use this to explain and motivate some of these results in dimensions one through three. \n  \n3:30-4:00 pm ET \nBreak/Discussion \n  \n4:00-5:30 pm ET \nSpeaker: Lukasz Fidkowski\, U Washington\, Physics \nTitle: Invertible Phases of Matter and Quantum Cellular Automata: Higher dimensions \nAbstract: We discuss the explicit construction of a non-trivial QCA in 3 dimensions\, one which takes the form of multiplication by a discrete Chern-Simons functional in an appropriate basis for the Hilbert space. We relate the non-trivialness of the QCA to the fact that the Chern-Simons action is not the integral of a gauge invariant local quantity. One property of this QCA is that it creates a specific non-trivial time reversal symmetry protected topological (SPT) phase when acting on a non-trivial tensor product state. Motivated by this\, we construct a general class of QCA in arbitrary dimensions based on time reversal protected SPTs\, and conjecture a general correspondence between unoriented cobordism (which classifies such SPTs) and QCA. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_102524/
LOCATION:Virtual
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-10.25.2024.docx-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241024T100000
DTEND;TZID=America/New_York:20241024T110000
DTSTAMP:20260614T000527
CREATED:20241018T143428Z
LAST-MODIFIED:20241018T144254Z
UID:10003595-1729764000-1729767600@cmsa.fas.harvard.edu
SUMMARY:Heterotic Little String Theories and Inequivalent Genus-One Fibrations
DESCRIPTION:Mathematical Physics and Algebraic Geometry Seminar \nSpeaker: Hamza Ahmed\, Northeastern University \nTitle: Heterotic Little String Theories and Inequivalent Genus-One Fibrations \nAbstract: Little String Theories (LSTs) are 6D Supersymmetric quantum field theories (SQFTs) with an additional physical relation called T-duality. This enables us to arrange them into equivalence classes\, where each equivalence class has 6D LSTs that lead to the same 5D effective theory when compactified on a circle. The problem of finding T-dual LSTs can be mapped to the problem of finding inequivalent genus-one fibrations of the same non-compact Calabi-Yau (CY) threefold. For T-dual theories\, certain field theory data is expected to match\, which then implies certain invariants of inequivalent fibrations. Focusing on theories with 8 supercharges (Heterotic LSTs)\, we use this geometry-field theory equivalence to study the T-duality landscape\, particularly in the case where the genus-one fiber does not have a section\, leading to what are called twisted T-dual theories. Based on the excellent agreement we find between the geometry and field theory arguments\, we conjecture the existence of a new class of twisted T-duals for which no geometric construction is known. \n  \n 
URL:https://cmsa.fas.harvard.edu/event/mathphys_102424/
LOCATION:Virtual
CATEGORIES:Mathematical Physics and Algebraic Geometry
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Mathematical-Physics-and-Algebraic-Geometry-10.24.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240918T090000
DTEND;TZID=America/New_York:20240918T103000
DTSTAMP:20260614T000527
CREATED:20240904T181255Z
LAST-MODIFIED:20250328T150446Z
UID:10003442-1726650000-1726655400@cmsa.fas.harvard.edu
SUMMARY:CMSA/Tsinghua Math-Science Literature Lecture: Marc Lackenby
DESCRIPTION:CMSA/Tsinghua Math-Science Literature Lecture \nDate: Wednesday\, September 18\, 2024 \nTime: 9:00 – 10:30 am ET \nLocation: Via Zoom Webinar \nSpeaker: Marc Lackenby\, University of Oxford \nTitle: The complexity of knots \nAbstract: In his final paper in 1954\, Alan Turing wrote `No systematic method is yet known by which one can tell whether two knots are the same.’ Within the next 20 years\, Wolfgang Haken and Geoffrey Hemion had discovered such a method. However\, the computational complexity of this problem remains unknown. In my talk\, I will give a survey on this area\, that draws on the work of many low-dimensional topologists and geometers. Unfortunately\, the current upper bounds on the computational complexity of the knot equivalence problem remain quite poor. However\, there are some recent results indicating that\, perhaps\, knots are more tractable than they first seem. Specifically\, I will explain a theorem that provides\, for each knot type K\, a polynomial p_K with the property that any two diagrams of K with n_1 and n_2 crossings differ by at most p_K(n_1) + p_K(n_2) Reidemeister moves. \n\nBeginning in Spring 2020\, the CMSA began hosting a lecture series on literature in the mathematical sciences\, with a focus on significant developments in mathematics that have influenced the discipline\, and the lifetime accomplishments of significant scholars.
URL:https://cmsa.fas.harvard.edu/event/mathscilit2024_ml/
LOCATION:Virtual
CATEGORIES:Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/Mathlit_Lackenby_8.5x11.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240507T140000
DTEND;TZID=America/New_York:20240507T150000
DTSTAMP:20260614T000527
CREATED:20240411T181320Z
LAST-MODIFIED:20240819T151524Z
UID:10000835-1715090400-1715094000@cmsa.fas.harvard.edu
SUMMARY:Real-time observables in horizon thermodynamics
DESCRIPTION:General Relativity Seminar \nSpeaker: Albert Law\, Stanford \nTitle: Real-time observables in horizon thermodynamics \nAbstract: Euclidean black hole 1-loop determinants have recently been shown to compute a renormalized thermal canonical partition function for free fields in Lorentzian signature. A key ingredient is a ‘quasinormal mode (QNM) character’\, whose Fourier transform equals the renormalized spectral density of the single-particle Hamiltonian. Using a static patch in de Sitter space as an example\, in this talk\, I will offer new perspectives on the QNM character\, including its connection with the local density of states for the single-particle quantum mechanical problem associated with the Klein-Gordon equation\, and its direct relationships with (thermal) correlators of the free fields. I will discuss how these considerations might point toward a generalization to interacting theories.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-5724/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-05.7.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240425T103000
DTEND;TZID=America/New_York:20240425T113000
DTSTAMP:20260614T000527
CREATED:20240416T133525Z
LAST-MODIFIED:20240422T185259Z
UID:10000888-1714041000-1714044600@cmsa.fas.harvard.edu
SUMMARY:The logarithmic double ramification locus
DESCRIPTION:Algebraic Geometry in String Theory Seminar \nSpeaker: Alessandro Chiodo\, IMJ-Paris Rive Gauche (Jussieu) \nTitle: The logarithmic double ramification locus \nAbstract: Given a family of smooth curves C -> S with a line bundle L on C\, it is natural to study the locus of points x in S where L_x is trivial on C_x. When the family is stable\, the definition can be extended\, not directly on the base scheme S\, but more naturally on a (logarithmic) blow-up S’ of S. The problem is in many ways analogue to the problem of defining a Néron model on the moduli space of stable curves (instead of a DVR). Over the past years\, David Holmes and his collaborators pioneered a new approach on a logarithmic modification of the entire moduli space of curves. In this talk\, we determine this logarithmic double ramification cycle and several variants and alternative presentations of it (work in collaboration with David Holmes).
URL:https://cmsa.fas.harvard.edu/event/agst-42524/
LOCATION:Virtual
CATEGORIES:Algebraic Geometry in String Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Algebraic-Geometry-in-String-Theory-04.25.2024.docx-2.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240423T100000
DTEND;TZID=America/New_York:20240423T110000
DTSTAMP:20260614T000527
CREATED:20240415T162430Z
LAST-MODIFIED:20240422T154105Z
UID:10000833-1713866400-1713870000@cmsa.fas.harvard.edu
SUMMARY:Quantum Energy Inequalities
DESCRIPTION:General Relativity Seminar \nSpeaker: Chris Fewster\, York University \nTitle: Quantum Energy Inequalities \nAbstract: Many theorems of mathematical relativity\, including singularity and positive mass theorems\, include the classical energy conditions among their hypotheses. However\, matter described by quantum field theory can violate the classical energy conditions and indeed there is no lower bound to the energy density at a given point as the quantum state is varied. Do the classical theorems apply to quantised matter? \nIn this talk I discuss Quantum Energy Inequalities\, lower bounds on averages of the energy density along timelike curves or over spacetime regions\, that have been proved in QFT and are the remnants of the classical energy conditions after quantisation. I will also discuss some of their consequences.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar_42324/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240416T110000
DTEND;TZID=America/New_York:20240416T120000
DTSTAMP:20260614T000527
CREATED:20240409T163938Z
LAST-MODIFIED:20240502T195940Z
UID:10000832-1713265200-1713268800@cmsa.fas.harvard.edu
SUMMARY:New Well-Posed Boundary Conditions for Semi-Classical Euclidean Gravity
DESCRIPTION:General Relativity Seminar \nSpeaker: Xiaoyi Liu\, UCSB \nTitle: New Well-Posed Boundary Conditions for Semi-Classical Euclidean Gravity \nAbstract: We consider four-dimensional Euclidean gravity in a finite cavity.  We point out that there exists a one-parameter family of boundary conditions\, parameterized by a real constant\, where a suitably Weyl-rescaled boundary metric is fixed\, and all give a well-posed elliptic system\, as opposed to the Dirichlet boundary condition. Focussing on static Euclidean solutions\, we derive a thermodynamic first law. Restricting to a spherical spatial boundary\, the infillings are flat space or the Schwarzschild solution and have similar thermodynamics to the Dirichlet case. We study the stability behavior of several geometries under these boundary conditions in both Euclidean and Lorentzian signatures and find two puzzles.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar_41624/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-04.16.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240322T090000
DTEND;TZID=America/New_York:20240322T103000
DTSTAMP:20260614T000527
CREATED:20240318T135251Z
LAST-MODIFIED:20240318T141920Z
UID:10001511-1711098000-1711103400@cmsa.fas.harvard.edu
SUMMARY:Non-Invertible Peccei-Quinn Symmetry and the Massless Quark Solution to the Strong CP Problem
DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Sungwoo Hong\, Korea Advanced Institute of Science and Technology (KAIST) \nTitle: Non-Invertible Peccei-Quinn Symmetry and the Massless Quark Solution to the Strong CP Problem \nAbstract: In this talk\, I will discuss a new solution to the strong CP problem\, one of the most important and challenging problems\, of the Standard Model (SM) based on the generalized global symmetry. To this end\, I will first show that there exist non-invertible chiral symmetries acting on quark fields once the SM is extended with gauged quark flavor symmetry. Interestingly enough\, such symmetries\, which we named them as “non-invertible Peccei-Quinn symmetries”\, exist only because the SM has the same number of generations as colors\, yet another feature that deserves a fundamental explanation. Then I discuss how these new generalized symmetries set the down Yukawa to be exactly zero and lead to a massless quark solution to the strong CP problem. Completion of the solution requires (i) generation of down quark Yukawas to be consistent with both observed quark mass spectrum and mixings and (ii) generation of O(1) CP violating phase called CKM phase\, crucially without destabilizing our solution to the strong CP problem. I will discuss that these rather non-trivial tasks can be achieved by a UV completion in an SU(9) quark color-flavor unification.
URL:https://cmsa.fas.harvard.edu/event/qm-32224/
LOCATION:Virtual
CATEGORIES:Quantum Matter
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QMMP-03.22.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240320T140000
DTEND;TZID=America/New_York:20240320T150000
DTSTAMP:20260614T000527
CREATED:20240130T215041Z
LAST-MODIFIED:20240321T140550Z
UID:10001519-1710943200-1710946800@cmsa.fas.harvard.edu
SUMMARY:Solving olympiad geometry without human demonstrations
DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Trieu H. Trinh\, Google Deepmind and NYU Dept. of Computer Science \nTitle: Solving olympiad geometry without human demonstrations \nAbstract: Proving mathematical theorems at the olympiad level represents a notable milestone in human-level automated reasoning\, owing to their reputed difficulty among the world’s best talents in pre-university mathematics. Current machine-learning approaches\, however\, are not applicable to most mathematical domains owing to the high cost of translating human proofs into machine-verifiable format. The problem is even worse for geometry because of its unique translation challenges\, resulting in severe scarcity of training data. We propose AlphaGeometry\, a theorem prover for Euclidean plane geometry that sidesteps the need for human demonstrations by synthesizing millions of theorems and proofs across different levels of complexity. AlphaGeometry is a neuro-symbolic system that uses a neural language model\, trained from scratch on our large-scale synthetic data\, to guide a symbolic deduction engine through infinite branching points in challenging problems. On a test set of 30 latest olympiad-level problems\, AlphaGeometry solves 25\, outperforming the previous best method that only solves ten problems and approaching the performance of an average International Mathematical Olympiad (IMO) gold medallist. Notably\, AlphaGeometry produces human-readable proofs\, solves all geometry problems in the IMO 2000 and 2015 under human expert evaluation and discovers a generalized version of a translated IMO theorem in 2004. \n 
URL:https://cmsa.fas.harvard.edu/event/nt-32024/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-03.20.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240315T100000
DTEND;TZID=America/New_York:20240315T113000
DTSTAMP:20260614T000527
CREATED:20240311T164549Z
LAST-MODIFIED:20240311T164549Z
UID:10002907-1710496800-1710502200@cmsa.fas.harvard.edu
SUMMARY:Monopoles\, scattering\, generalized symmetries
DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Diego Delmastro (Simons Center for Geometry and Physics) \nTitle: Monopoles\, scattering\, generalized symmetries\n \nAbstract: Gauge theory is a very mature subject by now. Surprisingly\, some of its symmetries have only been properly understood in the last couple of years. Specifically\, such theories typically have a very rich set of symmetries\, involving modern notions such as higher-form symmetries\, higher-group symmetries\, and categorical symmetries. A proper understanding of these generalized symmetries is not really crucial if we are interested in scattering processes involvingfundamental particles only\, but it does become quite essential if we want to add monopoles into the mix.  In this talk I will review where these generalized symmetries come from\, and how they impose constraints on scattering amplitudes of elementary particles against heavy monopoles. This will allow us to resolve a decades-old puzzle concerning such processes\, where incoming electrons appear to become fractional particles after the scattering event.
URL:https://cmsa.fas.harvard.edu/event/monopoles-scattering-generalized-symmetries/
LOCATION:Virtual
CATEGORIES:Quantum Matter
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/1710175391273-1be4453c-8fc6-4e08-84f5-51bec5d04ec1docx_1-2.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240308T090000
DTEND;TZID=America/New_York:20240308T100000
DTSTAMP:20260614T000527
CREATED:20240305T204031Z
LAST-MODIFIED:20240307T165344Z
UID:10001510-1709888400-1709892000@cmsa.fas.harvard.edu
SUMMARY:A model for studying the sign problem on quantum computers: Z(3) gauge theory with three fermion flavors in 1+1 dimensions
DESCRIPTION:Quantum Matter in Mathematics and Physics Seminar \nSpeaker: Semeon Valgushev (Iowa State University) \nTitle: A model for studying the sign problem on quantum computers: Z(3) gauge theory with three fermion flavors in 1+1 dimensions \nAbstract: Many properties of quantum field theories can be understood with the help of classical numerical methods. Yet there are several outstanding problems — most remarkably the behaviour of nuclear matter at finite density and out-of-equilibrium real-time dynamics — that require the use of quantum algorithms. We present a simple yet physically rich toy model of QCD/nuclear matter at finite density\, termed “QZD”\, where Z stands for Z(3) gauge theory coupled to Nf = 3 fermion flavors\, suitable for simulation on near-term quantum devices. We study it using tensor networks and find that in weak coupling the spectrum is that of the expected mesons and baryons\, although the corrections in weak coupling are nontrivial. In strong coupling\, besides the usual baryon\, the singlet meson is a baryon anti-baryon state. For two special values of the coupling constant\, the lightest baryon is degenerate with the lightest octet meson\, and the lightest singlet meson\, respectively.
URL:https://cmsa.fas.harvard.edu/event/qm-3824/
LOCATION:Virtual
CATEGORIES:Quantum Matter
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/1709829554146-a2e594b2-ba0b-4248-bd23-63c7f0f9e199docx_1-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240305T110000
DTEND;TZID=America/New_York:20240305T120000
DTSTAMP:20260614T000527
CREATED:20240229T165205Z
LAST-MODIFIED:20240813T154631Z
UID:10000827-1709636400-1709640000@cmsa.fas.harvard.edu
SUMMARY:High order WENO finite difference scheme  for Einstein-Yang-Mills equations
DESCRIPTION:General Relativity Seminar \nSpeaker: Yuewen Chen\, Tsinghua University \nTitle: High order WENO finite difference scheme  for Einstein-Yang-Mills equations \nAbstract: In this talk\, we will show the convergence analysis of the first-order finite difference scheme for static spherically symmetric $SU(2)$ Einstein-Yang-Mills (EYM) equations. We also construct a new WENO scheme for EYM.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-3524/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-GR-Seminar-03.05.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240220T093000
DTEND;TZID=America/New_York:20240220T103000
DTSTAMP:20260614T000527
CREATED:20240219T195817Z
LAST-MODIFIED:20240219T195829Z
UID:10000825-1708421400-1708425000@cmsa.fas.harvard.edu
SUMMARY:Asymptotic decay for defocusing semilinear wave equations on Schwarzschild spacetimes
DESCRIPTION:General Relativity Seminar \nSpeaker: He Mei\, Shenzhen University \nTitle: Asymptotic decay for defocusing semilinear wave equations on Schwarzschild spacetimes \nAbstract: In this talk\, I will present a work on the long time dynamics of solutions to the defocusing semilinear wave equations on the Schwarzschild black hole spacetimes. For sufficiently smooth and localized initial data\, we show that the solution decays in the domain of outer communication. The proof relies on a vector field method of Dafermos-Rodnianski together with Strichartz estimates for linear waves by Marzuola-Metcalfe-Tataru-Tohaneanu.
URL:https://cmsa.fas.harvard.edu/event/general-relativity-seminar-22024/
LOCATION:Virtual
CATEGORIES:General Relativity Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20240207T090000
DTEND;TZID=America/New_York:20240207T103000
DTSTAMP:20260614T000527
CREATED:20240103T172620Z
LAST-MODIFIED:20241212T160057Z
UID:10001103-1707296400-1707301800@cmsa.fas.harvard.edu
SUMMARY:CMSA/Tsinghua Math-Science Literature Lecture: Amie Wilkinson
DESCRIPTION:CMSA/Tsinghua Math-Science Literature Lecture \nProf. Amie Wilkinson gave a lecture in the CMSA/Tsinghua Math-Science Literature Lecture Series. \nDate: Wednesday\, February 7\, 2024 \nTime: 9:00–10:30 am ET \nTitle: Stretching and shrinking: 85 years of the Hopf argument for ergodicity\nAbstract:  The early 20th century witnessed an explosion of activity\, much of it centered at Harvard\, on rigorizing the property of ergodicity first proposed by Boltzmann in his 1898  Ergodic Hypothesis for ideal gases. Earlier\, in the 1880’s\, Henri Poincaré and Felix Klein had also initiated a study of discrete groups of hyperbolic isometries. The geodesics in hyperbolic manifolds were discovered to carry a rich structure\, first investigated from a topological perspective by Emil Artin and Marston Morse.  The time was ripe to investigate geodesics in hyperbolic manifolds from an ergodic theoretic (i.e.\, statistical) perspective\, and indeed Gustav Hedlund proved in 1934 that the geodesic flow for closed hyperbolic surfaces is ergodic.\n\nIn 1939\, Eberhard Hopf published a proof of the ergodicity of geodesic flows for negatively curved surfaces containing a novel method\, now known as the Hopf argument.  The Hopf argument\, a “soft” argument for ergodicity of systems with some hyperbolicity (the “stretching and shrinking” in the title) has since seen wide application in geometry\, representation theory and dynamics.  I will discuss three results relying on the Hopf argument:\n\nTheorem (E. Hopf\, 1939\, D. Anosov\, 1967): In a closed manifold of negative sectional curvatures\, almost every geodesic is directionally equidistributed.\n\nTheorem (G. Mostow\, 1968) Let M and N be closed hyperbolic manifolds of dimension at least 3\, and let f:M->N be a homotopy equivalence.  Then f is homotopic to a unique isometry.\n\nTheorem (R. Mañé\, 1983\, A. Avila- S. Crovisier- A.W.\, 2022) The C^1 generic symplectomorphism of a closed symplectic manifold with positive entropy is ergodic.\n  \n\nBeginning in Spring 2020\, the CMSA began hosting a lecture series on literature in the mathematical sciences\, with a focus on significant developments in mathematics that have influenced the discipline\, and the lifetime accomplishments of significant scholars. \n 
URL:https://cmsa.fas.harvard.edu/event/mathscilit2024_aw/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Mathlit_Wilkinson_letter.png
END:VEVENT
END:VCALENDAR