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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241120T100000
DTEND;TZID=America/New_York:20241120T230000
DTSTAMP:20260607T182938
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:20241120T120000
DTEND;TZID=America/New_York:20241120T130000
DTSTAMP:20260607T182938
CREATED:20241104T194035Z
LAST-MODIFIED:20241107T171413Z
UID:10003535-1732104000-1732107600@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar: Anurag Anshu
DESCRIPTION:CMSA Q&A Seminar \nSpeaker: Anurag Anshu\, Harvard University \nTopic: What is quantum complexity theory? \n  \n 
URL:https://cmsa.fas.harvard.edu/event/cmsaqa_112024/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Q-A-Seminar-11.20.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241120T163000
DTEND;TZID=America/New_York:20241120T173000
DTSTAMP:20260607T182938
CREATED:20241120T165843Z
LAST-MODIFIED:20241120T172458Z
UID:10003622-1732120200-1732123800@cmsa.fas.harvard.edu
SUMMARY:Perturbative Factorization Algebras
DESCRIPTION:Geometry and Quantum Theory Seminar \nSpeaker: Ahsan Khan\n\n\n\nTitle: Perturbative Factorization Algebras\n\nAbstract: In physics the starting point in studying a QFT is to write down an appropriate action functional. My talk will aim to sketch how this connects with the framework of factorization algebras.
URL:https://cmsa.fas.harvard.edu/event/quantumgeo_112024/
LOCATION:Science Center Hall E\, 1 Oxford Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Geometry and Quantum Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Geometry-Quantum-Theory-11.20.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241122T120000
DTEND;TZID=America/New_York:20241122T130000
DTSTAMP:20260607T182938
CREATED:20240919T144708Z
LAST-MODIFIED:20241118T172611Z
UID:10003525-1732276800-1732280400@cmsa.fas.harvard.edu
SUMMARY:Identity crises phenomena in the large cardinal hierarchy
DESCRIPTION:Member Seminar \nSpeaker: Alejandro Poveda \nTitle: Identity crises phenomena in the large cardinal hierarchy\n\nAbstract: It is well-known that certain mathematical questions cannot be answered on the grounds of the standard foundation of mathematics. Large cardinal axioms constitute a series of postulates about the higher infinite which permit to classify these undecidable problems in a coherent hierarchy way. Specifically\, large cardinals together with ZFC (the standard axiomatic of Mathematics) provide a complete classification of all mathematical theories according to the so-called consistency strength. One of the main tenets of modern set theory has been to investigate how the large-cardinal hierarchy is organized across the mathematical universe. To a large extent this hierarchy is nicely disposed and such a disposition is unambiguous (i.e.\, immune to the independence phenomenon).\n\nIn an unexpected turn of events\, in the late 70’s Magidor discovered the identity crisis phenomena of the large cardinal hierarchy. Magidor proved that certain strata of the hierarchy are susceptible to be modified via Cohen’s method of forcing. Specifically\, he showed that the first strongly compact cardinal can be either the first measurable cardinal or the first supercompact cardinal. It turns out that the first measurable is always much smaller than the first supercompact. These discrepancies on the identity of the first strongly compact cardinal were termed by Magidor the Identity Crisis Phenomenon.\n\nIn this talk I plan to provide an introduction to the world of large cardinals keeping an eye on the identity crises phenomena. Time permitting\, I’ll present a few recent results answering questions by Magidor and discuss their connection with Woodin’s Ultimate-L Conjecture.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-112224/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Member-Seminar-11.22.24_Page_1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241125T093000
DTEND;TZID=America/New_York:20241125T110000
DTSTAMP:20260607T182938
CREATED:20241017T184932Z
LAST-MODIFIED:20241122T152145Z
UID:10003615-1732527000-1732532400@cmsa.fas.harvard.edu
SUMMARY:Foundation Seminar
DESCRIPTION:Foundation Seminar (Joint Seminar with BHI) \n\nTitle: Searching for Dark Matter in the Sky \nAbstract: Astrophysical and cosmological observations have allowed us to measure the abundance of dark matter and have provided important information on its properties. I will discuss past\, present and future efforts to map the gravitational footprint of dark matter throughout the cosmos\, and what such studies can (and cannot) tell us about dark matter’s fundamental nature. I will also review how even tiny non-gravitational interactions of dark and visible matter could lead to a range of “indirect detection” signals\, and outline the status and prospects of searches for such signals\, with a focus on the next decade or so.
URL:https://cmsa.fas.harvard.edu/event/foundation-seminar_112524/
LOCATION:Black Hole Initiative\, 20 Garden Street\, Cambridge MA\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Foundation Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/11.25.24_Tracy-Slatyer_Joint-CMSA-Template-Real-Estate-Flyer-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241125T163000
DTEND;TZID=America/New_York:20241125T173000
DTSTAMP:20260607T182938
CREATED:20240903T195237Z
LAST-MODIFIED:20241119T192853Z
UID:10003439-1732552200-1732555800@cmsa.fas.harvard.edu
SUMMARY:Mathematical Structures of Scattering Amplitudes
DESCRIPTION:Colloquium \nSpeaker: Anastasia Volovich\, Brown University \nTitle: Mathematical Structures of Scattering Amplitudes \nAbstract: Planar N=4 Yang-Mills scattering amplitudes have been computed to very high loop order. They have many remarkable properties that have sparked interest from mathematicians working on combinatorics\, algebraic geometry\, and number theory. At the same time\, several methods that have been developed for N=4 Yang-Mills can often be applied to more general quantum field theories\, including QCD. I will overview some of these exciting developments.
URL:https://cmsa.fas.harvard.edu/event/colloquium-112524/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-11.25.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241202T163000
DTEND;TZID=America/New_York:20241202T173000
DTSTAMP:20260607T182938
CREATED:20240903T195308Z
LAST-MODIFIED:20241126T142827Z
UID:10003440-1733157000-1733160600@cmsa.fas.harvard.edu
SUMMARY:Computability on $\mathbb R$ and other continuum-size structures
DESCRIPTION:Colloquium \nSpeaker: Russell Miller\, CUNY \nTitle: Computability on $\mathbb R$ and other continuum-size structures \nAbstract: We begin by recalling the notion of a computable function on the real numbers $\mathbb R$\, developed independently by Gregorczyk and Lacombe over sixty years ago. Using this notion\, we note that the real numbers that are themselves computable form a countable subfield of $\mathbb R$ with exactly the same first-order properties as $\mathbb R$ itself. (Logicians would therefore call it an \emph{elementary subfield}.) So\, in a first-order sense\, everything that happens in $\mathbb R$ is already exemplified in this much nicer subfield. However\, even when one knows that an existential statement holds for all parameters\, it may be impossible (both in $\mathbb R$ and in the subfield) to give a computable procedure for producing witnesses. Similar results hold in $\mathbb C$. \nWe will then turn to a different continuum-sized structure: the absolute Galois group $\operatorname{Gal}(\mathbb Q)$ of the rational numbers. Once again the computable elements of this group form a subgroup\, but now it is an open problem whether the group and the subgroup have the same first-order theory\, let alone whether this is an elementary subgroup. (If they do have the same theory\, this would put nice upper bounds on the complexity of the theory of $\operatorname{Gal}(\mathbb Q)$.) However\, using joint work with Kundu\, we can show that once again there is no computable procedure for producing witnesses to the truth of (true) existential statements\, either in the full group or in the subgroup.
URL:https://cmsa.fas.harvard.edu/event/colloquium-12224/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-12.2.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241203T161500
DTEND;TZID=America/New_York:20241203T181500
DTSTAMP:20260607T182938
CREATED:20240917T162348Z
LAST-MODIFIED:20241104T152406Z
UID:10003517-1733242500-1733249700@cmsa.fas.harvard.edu
SUMMARY:Factorization Homology
DESCRIPTION:Geometry and Quantum Theory Seminar \nSpeakers: Sunghyuk Park and Vasily Krylov\, Harvard CMSA \nTitle: Factorization Homology
URL:https://cmsa.fas.harvard.edu/event/quantumgeo_12324/
LOCATION:Science Center Hall E\, 1 Oxford Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Geometry and Quantum Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241204T140000
DTEND;TZID=America/New_York:20241204T150000
DTSTAMP:20260607T182938
CREATED:20240907T180227Z
LAST-MODIFIED:20241212T205959Z
UID:10003410-1733320800-1733324400@cmsa.fas.harvard.edu
SUMMARY:Can Transformers Reason Logically? A Study in SAT-Solving
DESCRIPTION:New Technologies in Mathematics Seminar \nSpeaker: Leyan Pan\, Georgia Tech \nTitle: Can Transformers Reason Logically? A Study in SAT-Solving \nAbstract: Transformer-based LLMs have apparently demonstrated capabilities that resembles human reasoning. In our recent work\, we investigated the Boolean reasoning abilities of decoder-only Transformers equipped with Chain-of-Thought\, establishing that a Transformer model can decide all 3-SAT instances up to a bounded size (i.e.\, number of variables and clauses). In this talk\, I will first review recent studies that formally examine the expressiveness of Transformer models. Next\, I will explain how we establish an equivalence between Chain-of-Thought reasoning and algorithm\, in our case\, the DPLL SAT-solving algorithm. I will then discuss how to encode 3-SAT formulas and partial assignments as vectors so that the high-level operations in DPLL can be represented as vector operations and implemented using attention mechanisms within Transformers. Finally\, I will present experimental results that support our theoretical predictions. I will also address why standard Transformers can only solve reasoning problems of bounded length\, leading to failures in length-generalization\, and discuss potential solutions to overcome this limitation.
URL:https://cmsa.fas.harvard.edu/event/newtech_12424/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-NTM-Seminar-12.4.24.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241206T120000
DTEND;TZID=America/New_York:20241206T130000
DTSTAMP:20260607T182938
CREATED:20240919T144747Z
LAST-MODIFIED:20241203T164917Z
UID:10003527-1733486400-1733490000@cmsa.fas.harvard.edu
SUMMARY:On the Coulomb branch scaling dimensions of 4d N=2 SCFTs
DESCRIPTION:Member Seminar \nSpeaker: Robert Moscrop \nTitle: On the Coulomb branch scaling dimensions of 4d N=2 SCFTs \nAbstract: To each four dimensional N=2 superconformal field theory of rank-r\, one can associate an r-tuple of numbers given by the scaling dimensions of a special set of protected operators whose VEVs parameterise the Coulomb branch. In this talk\, I will demonstrate how the special geometry of the Coulomb branch heavily constrains not only the values of the scaling dimensions\, but also the possible r-tuples of such numbers that can occur.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-120624/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Member-Seminar-12.6.24.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241206T160000
DTEND;TZID=America/New_York:20241206T170000
DTSTAMP:20260607T182938
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:20241210T093000
DTEND;TZID=America/New_York:20241210T110000
DTSTAMP:20260607T182938
CREATED:20250123T201841Z
LAST-MODIFIED:20250123T202831Z
UID:10003669-1733823000-1733828400@cmsa.fas.harvard.edu
SUMMARY:Quantum Effects Inside Black Holes
DESCRIPTION:Joint CMSA/BHI Foundation Seminar \nLocation: BHI seminar room \n\nSpeaker: Noa Zilberman\, Princeton \nTitle: Quantum Effects Inside Black Holes \n\n\nAbstract: Astrophysical black holes are known to be rotating. Within classical General Relativity\, the simplest spacetime solution (the Kerr solution) describing a rotating black hole reveals a traversable passage through an inner horizon – which in turn may lead to another external universe. But does this remain the case when taking quantum effects into account? \nAnswering this question\, along others\, requires one to understand the manner in which quantum energy fluxes affect the internal geometry of a black hole. It has been widely anticipated\, yet inconclusive (till this work)\, that such effects would diverge at the inner horizon of a spinning black hole. This divergence\, if indeed takes place\, may drastically affect the internal black hole geometry\, potentially preventing the inner horizon traversability. Clarifying this issue requires the computation of the quantum energy fluxes in black hole interiors. However\, this has been a serious challenge for decades. \nUsing a combination of old and new methods\, we have managed to compute the quantum energy fluxes at the inner horizon of a spinning black hole\, in a vacuum state corresponding to an evaporating black hole. We found that these fluxes are either positive or negative\, depending on the black hole spin (and polar angle). The sign of these fluxes may be crucial to the nature of their backreaction on the geometry (as should be dictated by the semiclassical Einstein equation). \nIn this seminar\, we shall briefly describe the basic framework of semiclassical general relativity and the renormalization procedure\, and then present our novel results for the quantum fluxes at the inner horizon of a rotating black hole\, briefly mentioning possible implications for the inner horizon traversability.
URL:https://cmsa.fas.harvard.edu/event/foundation_21025/
LOCATION:Black Hole Initiative\, 20 Garden Street\, Cambridge MA\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Foundation Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20241213T100000
DTEND;TZID=America/New_York:20241213T113000
DTSTAMP:20260607T182938
CREATED:20240907T194348Z
LAST-MODIFIED:20241210T165540Z
UID:10003474-1734084000-1734089400@cmsa.fas.harvard.edu
SUMMARY:Nonlinear Bosonization of (Non-)Fermi Liquids
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Yi-Hsien Du (MIT) \nTitle: Nonlinear Bosonization of (Non-)Fermi Liquids \nAbstract: Fermi liquid theory is a cornerstone of condensed matter physics. I will show how to formulate Fermi liquid theory as an effective field theory. In this approach\, the space of low-energy states of a Fermi liquid is identified with a coadjoint orbit of the group of canonical transformations. The method naturally leads to a nonlinear bosonized description of the Fermi liquid with nonlinear corrections fixed by the geometry of the Fermi surface. I will present that the resulting local effective field theory captures both linear and nonlinear effects in Landau’s Fermi liquid theory. The approach can be extended to encompass non-Fermi liquids\, which correspond to strongly interacting fixed points obtained by deforming Fermi liquids with relevant interactions. I will also discuss how Berry curvature can be captured in the effective field theory approach.
URL:https://cmsa.fas.harvard.edu/event/qm_121324/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-12.13.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250122T120000
DTEND;TZID=America/New_York:20250122T130000
DTSTAMP:20260607T182938
CREATED:20241218T144410Z
LAST-MODIFIED:20250107T192219Z
UID:10003652-1737547200-1737550800@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar: Edgar Shaghoulian
DESCRIPTION:CMSA Q&A Seminar \nSpeaker: Edgar Shaghoulian\, UC Santa Cruz \nTopic: What are the main questions in quantum gravity today?
URL:https://cmsa.fas.harvard.edu/event/cmsaqa_12225/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Copy-of-CMSA-Q-A-Seminar-1.22.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250127T093000
DTEND;TZID=America/New_York:20250127T103000
DTSTAMP:20260607T182938
CREATED:20250123T201747Z
LAST-MODIFIED:20250127T204324Z
UID:10003668-1737970200-1737973800@cmsa.fas.harvard.edu
SUMMARY:Joint BHI/CMSA Foundation Seminar: Quantum Criticality in Black Hole Dynamics
DESCRIPTION:Joint BHI/CMSA Foundation Seminar \nLocation: BHI Seminar Room \nSpeaker: Uri Kol\, Harvard CMSA \n\nTitle: Quantum Criticality in Black Hole Dynamics \nAbstract: Black hole perturbation theory captures a few important effects in the dynamics of binary mergers\, such as tidal deformations and the decay of ringdown modes\, as well as the physics of the photon ring. However\, deriving qualitative results that lead to robust predictions in this theory remains a challenging problem\, despite a rich scientific history.\nMotivated by the immense experimental progress made in the field over the past decade\, in this talk I will describe a new critical phenomenon emerging in the theory of perturbations around Kerr black holes. A critical point is identified at zero black hole temperature\, giving rise to a wide regime at finite temperatures which is dominated by critical perturbations. As in quantum many-body systems\, the physics in the critical regime is described exclusively by a set of critical exponents\, therefore leading to robust predictions that are unique to the Kerr metric.
URL:https://cmsa.fas.harvard.edu/event/foundation_12725/
LOCATION:Black Hole Initiative\, 20 Garden Street\, Cambridge MA\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Foundation Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-BHI-Joint-Foundations-Seminar-1.27.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250127T150000
DTEND;TZID=America/New_York:20250127T160000
DTSTAMP:20260607T182938
CREATED:20240907T194212Z
LAST-MODIFIED:20250124T171827Z
UID:10003471-1737990000-1737993600@cmsa.fas.harvard.edu
SUMMARY:A homotopy of 2d SCFTs and an implication for Topological Modular Forms
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Vivek Saxena (YITP Stony Brook and NHETC Rutgers) \nTitle: A homotopy of 2d SCFTs and an implication for Topological Modular Forms \nAbstract: The Segal-Stolz-Teichner conjecture states that there exists an isomorphism between deformation classes of two-dimensional N=(0\,1) superconformal field theories (SCFTs) and generalized cohomology classes known as Topological Modular Forms (TMFs). Such 2d N=(0\,1) SCFTs arise naturally in physics as worldsheet theories of (possibly compactified) heterotic strings. Recently\, this connection was used to prove the absence of global anomalies in heterotic string theories and make predictions about topological terms in their low-energy effective actions\, among other things. \nIn this talk\, after giving a brief overview of these ideas\, I will describe a physics ”proof” (using methods from 2d CFT) of a mathematical conjecture of Tachikawa and Yamashita about TMF classes in degree 31. Specifically\, by examining the two worldsheet theories corresponding to two T-dual nine-dimensional spacetime non-supersymmetric heterotic string theories (namely the $(E_8)_1 \times (E_8)_1$ theory and the $(E_8)_2$ theory)\, I will argue that the $(E_8)_2$ theory corresponds to the unique nontrivial torsion element $[(E_8)_2]$ of TMF$^{31}$ with zero mod-2 elliptic genus.
URL:https://cmsa.fas.harvard.edu/event/qft_12725/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-1.27.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250128T161500
DTEND;TZID=America/New_York:20250128T181500
DTSTAMP:20260607T182938
CREATED:20250124T150923Z
LAST-MODIFIED:20250124T151709Z
UID:10003653-1738080900-1738088100@cmsa.fas.harvard.edu
SUMMARY:Review of the excision property in factorization homology
DESCRIPTION:Geometry and Quantum Theory Seminar \nSpeaker: Keyou Zeng\, Harvard CMSA \nTitle: Review of the excision property in factorization homology
URL:https://cmsa.fas.harvard.edu/event/quantumgeo_12825/
LOCATION:Science Center 507\, 1 Oxford Street\, Cambridge\, 02138
CATEGORIES:Geometry and Quantum Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Geometry-Quantum-Theory-1.28.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250131T120000
DTEND;TZID=America/New_York:20250131T130000
DTSTAMP:20260607T182938
CREATED:20250127T180141Z
LAST-MODIFIED:20250127T180704Z
UID:10003638-1738324800-1738328400@cmsa.fas.harvard.edu
SUMMARY:Smooth projective fibrations over the projective line and their sections
DESCRIPTION:Member Seminar \nSpeaker: Iacopo Brivio \nTitle: Smooth projective fibrations over the projective line and their sections \nAbstract: Suppose $f\colon X\to \mathbf{CP}^1$ is a smooth projective fibration\, is it then true that $f$ has a section? This deceptively simple result was established by Seidel and McDuff using deep methods of symplectic geometry. Alex Pieloch recently generalized this to morphisms with at most one singular fibers and furthermore showed that $X$ uniruled\, that is covered by images of $\mathbf{P}^1$. In my talk I will explain how to recover Pieloch’s result from the Good Minimal Model Conjecture. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-13125/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Member-Seminar-1.31.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250203T150000
DTEND;TZID=America/New_York:20250203T160000
DTSTAMP:20260607T182938
CREATED:20250124T171714Z
LAST-MODIFIED:20250131T150210Z
UID:10003672-1738594800-1738598400@cmsa.fas.harvard.edu
SUMMARY:Topological to Gravitational Leptogenesis\, via Ultra Unification 
DESCRIPTION:Quantum Field Theory and Physical Mathematics Seminar \nSpeaker: Juven Wang (LIMS\, Royal Institution) \nTitle: Topological to Gravitational Leptogenesis\, via Ultra Unification \nAbstract: We propose a new mechanism for leptogenesis\, named Topological Leptogenesis\, in which dark matter consists of topological order\, so gapped anyon excitations decay to generate the Standard Model lepton asymmetry. Topological Leptogenesis is in contrast with the Majorana Leptogenesis and Gravitational Leptogenesis. In the standard Majorana Leptogenesis\, the baryon asymmetry of the present universe is attributed to the leptogenesis from the sterile right-handed neutrino with heavy Majorana fermion mass decaying into the Standard Model leptons in the very early universe\, while the electroweak sphaleron causes baryogenesis at a later time. Gravitational leptogenesis can be regarded as an intermediate step between Majorana particle leptogenesis and topological non-particle leptogenesis. Topological Leptogenesis is derived out of Ultra Unification constructed from a mod 16 nonperturbative global anomaly cancellation that adds a symmetry-extended anomalous gapped topological quantum field theory (TQFT) to the Standard Model. Thus (1) the Beyond-the-Standard-Model (BSM) Dark Matter partly consists of Topological Order with low energy TQFT\, while there are anyon string excitations above the energy gap. (2) The 5th force is a Topological Discrete Gauge Force of (B-L) that mediates between the Standard Model particles\, the BSM Topological Order\, and gapped anyon string non-particle excitations. \nBased on https://arxiv.org/abs/2501.00607\, https://arxiv.org/abs/2012.15860\, https://arxiv.org/abs/2302.14862 and https://arxiv.org/abs/2411.05786.
URL:https://cmsa.fas.harvard.edu/event/qft_2325/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Quantum Field Theory and Physical Mathematics
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-QFT-and-Physical-Mathematics-2.3.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250203T163000
DTEND;TZID=America/New_York:20250203T173000
DTSTAMP:20260607T182938
CREATED:20240903T194951Z
LAST-MODIFIED:20250130T165403Z
UID:10003434-1738600200-1738603800@cmsa.fas.harvard.edu
SUMMARY:Rational approximation and the AAA algorithm
DESCRIPTION:Colloquium \nSpeaker: Nick Trefethen\, Harvard University \nTitle: Rational approximation and the AAA algorithm \nApproximation by rational functions used to be mainly a theoretical subject\, but with the introduction of the AAA algorithm in 2018\, it became computationally practical and indeed easy. The implications for what we can do numerically are enormous. This talk will outline the algorithm and demonstrate its application to a collection of problems. We can also use it to demonstrate the potential theory that underlies the theory of rational approximation\, a topic that goes back to Joseph Walsh here at Harvard a century ago.
URL:https://cmsa.fas.harvard.edu/event/colloquium-2325/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-2.3.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250204T161500
DTEND;TZID=America/New_York:20250204T181500
DTSTAMP:20260607T182938
CREATED:20240917T160739Z
LAST-MODIFIED:20250124T152130Z
UID:10003513-1738685700-1738692900@cmsa.fas.harvard.edu
SUMMARY:Blob homology
DESCRIPTION:Geometry and Quantum Theory Seminar \nSpeaker: Sunghyuk Park\, Harvard CMSA \nTitle: Blob homology
URL:https://cmsa.fas.harvard.edu/event/quantumgeo_2425/
LOCATION:Science Center 507\, 1 Oxford Street\, Cambridge\, 02138
CATEGORIES:Geometry and Quantum Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Geometry-Quantum-Theory-2.4.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250205T120000
DTEND;TZID=America/New_York:20250205T130000
DTSTAMP:20260607T182938
CREATED:20241104T201420Z
LAST-MODIFIED:20250106T151435Z
UID:10003591-1738756800-1738760400@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar: Subir Sachdev
DESCRIPTION:CMSA Q&A Seminar \n\nSpeaker: Subir Sachdev\, Harvard University \nTopic: What is a quantum critical region?
URL:https://cmsa.fas.harvard.edu/event/cmsaqa_2525/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Q-A-Seminar-2.5.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250207T140000
DTEND;TZID=America/New_York:20250207T154500
DTSTAMP:20260607T182938
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:20250210T093000
DTEND;TZID=America/New_York:20250210T103000
DTSTAMP:20260607T182938
CREATED:20250123T204528Z
LAST-MODIFIED:20250127T204354Z
UID:10003667-1739179800-1739183400@cmsa.fas.harvard.edu
SUMMARY:Joint BHI/CMSA Foundation Seminar: Quantum Effects Inside Black Holes
DESCRIPTION:Joint BHI/CMSA Foundation Seminar \nLocation: BHI seminar room \nSpeaker: Noa Zilberman (Princeton University) \nTitle: Quantum Effects Inside Black Holes \nAbstract: Astrophysical black holes are known to be rotating. Within classical General Relativity\, the simplest spacetime solution (the Kerr solution) describing a rotating black hole reveals a traversable passage through an inner horizon – which in turn may lead to another external universe. But does this remain the case when taking quantum effects into account? \nAnswering this question\, along others\, requires one to understand the manner in which quantum energy fluxes affect the internal geometry of a black hole. It has been widely anticipated\, yet inconclusive (till this work)\, that such effects would diverge at the inner horizon of a spinning black hole. This divergence\, if indeed takes place\, may drastically affect the internal black hole geometry\, potentially preventing the inner horizon traversability. Clarifying this issue requires the computation of the quantum energy fluxes in black hole interiors. However\, this has been a serious challenge for decades. \nUsing a combination of old and new methods\, we have managed to compute the quantum energy fluxes at the inner horizon of a spinning black hole\, in a vacuum state corresponding to an evaporating black hole. We found that these fluxes are either positive or negative\, depending on the black hole spin (and polar angle). The sign of these fluxes may be crucial to the nature of their backreaction on the geometry (as should be dictated by the semiclassical Einstein equation). \nIn this seminar\, we shall briefly describe the basic framework of semiclassical general relativity and the renormalization procedure\, and then present our novel results for the quantum fluxes at the inner horizon of a rotating black hole\, briefly mentioning possible implications for the inner horizon traversability. \n 
URL:https://cmsa.fas.harvard.edu/event/foundation_21025-2/
LOCATION:Black Hole Initiative\, 20 Garden Street\, Cambridge MA\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Foundation Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-BHI-Joint-Foundations-Seminar-2.10.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250210T110000
DTEND;TZID=America/New_York:20250210T120000
DTSTAMP:20260607T182938
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:20250210T163000
DTEND;TZID=America/New_York:20250210T173000
DTSTAMP:20260607T182938
CREATED:20240903T195201Z
LAST-MODIFIED:20250130T165640Z
UID:10003438-1739205000-1739208600@cmsa.fas.harvard.edu
SUMMARY:AI in math and theoretical physics: Status and prospects
DESCRIPTION:Colloquium \nSpeaker: Michael Douglas\, Harvard CMSA \nTitle: AI in math and theoretical physics: status and prospects \nAbstract: AI is making great progress and has the potential to change how we work in unprecedented ways. In this talk I will survey a few recent works which illustrate the state of the art\, some from my own research\, some developed at the CMSA’s recent program on Mathematics and Machine Learning. I will then report on current developments in AI and speculate on how they will affect our work in the next few years. \n 
URL:https://cmsa.fas.harvard.edu/event/colloquium-21025/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Colloquium
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Colloquium-2.10.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250211T161500
DTEND;TZID=America/New_York:20250211T181500
DTSTAMP:20260607T182938
CREATED:20250124T152335Z
LAST-MODIFIED:20250204T212412Z
UID:10003654-1739290500-1739297700@cmsa.fas.harvard.edu
SUMMARY:Discussion of Integrating quantum groups over surfaces
DESCRIPTION:Geometry and Quantum Theory Seminar \nSpeaker: Ben Gammage\, Harvard University \nTitle: Discussion of Integrating quantum groups over surfaces \nhttps://arxiv.org/abs/1501.04652
URL:https://cmsa.fas.harvard.edu/event/quantumgeo_21125/
LOCATION:Science Center 507\, 1 Oxford Street\, Cambridge\, 02138
CATEGORIES:Geometry and Quantum Theory Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Geometry-Quantum-Theory-2.11.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250212T120000
DTEND;TZID=America/New_York:20250212T130000
DTSTAMP:20260607T182938
CREATED:20241104T145634Z
LAST-MODIFIED:20250131T154821Z
UID:10003534-1739361600-1739365200@cmsa.fas.harvard.edu
SUMMARY:CMSA Q&A Seminar: Javier Gomez-Serrano
DESCRIPTION:CMSA Q&A Seminar \nSpeaker: Javier Gomez-Serrano\, Brown University \nTopic: Please tell us about the Millennium prize problem for Navier-Stokes and segue from that into ML?
URL:https://cmsa.fas.harvard.edu/event/cmsaqa_21225/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:CMSA Q&A Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Q-A-Seminar-2.12.2025.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250212T140000
DTEND;TZID=America/New_York:20250212T150000
DTSTAMP:20260607T182938
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:20250214T120000
DTEND;TZID=America/New_York:20250214T130000
DTSTAMP:20260607T182938
CREATED:20241211T171913Z
LAST-MODIFIED:20250210T162218Z
UID:10003640-1739534400-1739538000@cmsa.fas.harvard.edu
SUMMARY:Jack polynomials and enumeration of non-orientable maps
DESCRIPTION:Member Seminar \nSpeaker: Houcine Ben Dali\, Harvard CMSA \nTitle: Jack polynomials and enumeration of non-orientable maps \nAbstract: A map is a graph embedded on a surface\, which may be orientable or not. The representation theory of the symmetric group can be used to write the generating series of maps on orientable surfaces using Schur symmetric functions. \nSeveral conjectures suggest that Jack polynomials—a one-parameter deformation of Schur functions—are related to the enumeration of non-orientable maps counted with a “non-orientability” weight. In this talk\, I will discuss some of these conjectures and present recent progress in this direction.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-21425/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Member-Seminar-2.14.25-1.png
END:VEVENT
END:VCALENDAR