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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250425T030000
DTEND;TZID=America/New_York:20250425T160000
DTSTAMP:20260430T232845
CREATED:20250422T134510Z
LAST-MODIFIED:20250422T140503Z
UID:10003713-1745550000-1745596800@cmsa.fas.harvard.edu
SUMMARY:Adversarial KA
DESCRIPTION:Freedman CMSA Seminar \nSpeaker: Slava Dzhenzher\, MIPT \nTitle: Adversarial KA \nAbstract: Regarding the representation theorem of Kolmogorov and Arnold (KA) as an algorithm for representing or «expressing» functions\, we test its robustness by analyzing its ability to withstand adversarial attacks. We find KA to be robust to countable collections of continuous adversaries\, but unearth a question about the equi-continuity of the outer functions that\, so far\, obstructs taking limits and defeating continuous groups of adversaries. This question on the regularity of the outer functions is relevant to the debate over the applicability of KA to the general theory of NNs. Based on  https://arxiv.org/abs/2504.05255 \n  \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_42525/
LOCATION:Virtual
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-4.25.25.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250312T150000
DTEND;TZID=America/New_York:20250312T170000
DTSTAMP:20260430T232845
CREATED:20250210T183743Z
LAST-MODIFIED:20250307T175626Z
UID:10003711-1741791600-1741798800@cmsa.fas.harvard.edu
SUMMARY:Freedman CMSA Seminar: Michael Freedman (CMSA) & Elia Portnoy (MIT)
DESCRIPTION:Freedman CMSA Seminar \nSpeaker: Michael Freedman\, Harvard CMSA (3:00–4:00 pm ET) \nTitle: How many links can you fit in a box? \nAbstract: I’ll discuss a “made up” problem on the interface of topology and packing\, which may well be classified as “recreational math”.  Here is the first question suppose you have a unit box\, how many unlinked (split) copies of the Hopf link (c_1\,i\,c_2\,i) and be embedded so that for each copy the two components c_1\,i and c_2\,i maintain a distance of at least  some fixed \epsilon >0. Is this number even finite? \n  \nSpeaker: Elia Portnoy\, MIT (4:00–5:00 pm ET) \nTitle: An explicit packing of links in a box and some progress in quantitative embeddings \nAbstract: Following Freedman’s talk\, I’ll begin by showing how to pack a large number of links in a box with certain geometric and topological constraints (joint with Fedya Manin). If time permits\, I’ll also discuss some progress and open questions for the following quantitative embedding problem: given a simplicial complex X\, what is the smallest size of a map from X to R^n so that the preimage of each unit ball intersects a small constant number of simplices? \n 
URL:https://cmsa.fas.harvard.edu/event/freedman_31225/
LOCATION:Hybrid – G10
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-3.12.25.docx-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20250207T140000
DTEND;TZID=America/New_York:20250207T154500
DTSTAMP:20260430T232845
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:20241206T160000
DTEND;TZID=America/New_York:20241206T170000
DTSTAMP:20260430T232845
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:20241115T143000
DTEND;TZID=America/New_York:20241115T173000
DTSTAMP:20260430T232845
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:20241025T143000
DTEND;TZID=America/New_York:20241025T173000
DTSTAMP:20260430T232845
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:20240913T143000
DTEND;TZID=America/New_York:20240913T170000
DTSTAMP:20260430T232845
CREATED:20240723T202450Z
LAST-MODIFIED:20240911T134726Z
UID:10003401-1726237800-1726246800@cmsa.fas.harvard.edu
SUMMARY:Freedman CMSA Seminar
DESCRIPTION:Freedman CMSA Seminar \n  \n2:00-3:30 pm ET \nSpeaker: Mike Freedman\, Harvard CMSA \nTitle: Detecting hidden structures in linear maps \nAbstract: I’ll consider the problem of detecting spectral features and tensor structures within linear maps both in a quantum and classical contexts. In the quantum context there is the question of whether a Hamiltonian is local\, and if so\, local in distinct coordinate systems (a “duality”). Also\, in the case of a unitary described by a quantum circuit\, does it possess unusual spectral features or tensor structure? In ML one optimizes many linear maps. How would we know – and would we care – if the resulting maps (approximately) tensor factored? \n  \n3:30-4:00 pm ET \nBreak/Discussion \n  \n4:00-5:30 pm ET \nSpeaker: Ryan O’Donnell\, Carnegie Mellon University \nTitle: Quartic quantum speedups for planted inference \nAbstract: Consider the following task (“noisy 4XOR”)\, arising in CSPs\, optimization\, and cryptography. There is a ‘secret’ Boolean vector x in {-1\,+1}^n. One gets m randomly chosen pairs (S\, b)\, where S is a set of 4 coordinates from [n] and b is x^S := prod_{i in S} x_i with probability 1-eps\, and -x^S with probability eps. Can you tell the difference between the cases eps = 0.1 and eps = 0.5? \nIt depends on m. The best known algorithms use the “Kikuchi method” and run in time ~n^L when m ~ n^2/L. We will review this method\, and also show that the running time can be improved to roughly n^{L/4} with a quantum algorithm. \nJoint work with Alexander Schmidhuber (MIT)\, Robin Kothari (Google)\, and Ryan Babbush (Google).
URL:https://cmsa.fas.harvard.edu/event/freedman_91324/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Freedman Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Freedman-Seminar-09.13.2024.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231215T120000
DTEND;TZID=America/New_York:20231215T130000
DTSTAMP:20260430T232845
CREATED:20240227T111152Z
LAST-MODIFIED:20240227T111152Z
UID:10002876-1702641600-1702645200@cmsa.fas.harvard.edu
SUMMARY:On compactness phenomena
DESCRIPTION:Member Seminar \nSpeaker: Alejandro Poveda \nTitle: On compactness phenomena \nAbstract: In this presentation I shall be preoccupied with compactness phenomena in set theory. Compactness is the phenomenon by which the local properties of a mathematical structure determine its global behavior. This phenomenon is intrinsic to the very architecture of the mathematical universe and manifests to us in a cornucopia of forms. Over the past fifty years\, the study of compactness phenomena has been a cornerstone of research in set theory. This talk will present recent discoveries regarding compactness principles\, spanning classical themes like the tree property and stationary reflection\, while also forging novel connections with other topics\, such as Woodin’s HOD Conjecture.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-121523/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231208T120000
DTEND;TZID=America/New_York:20231208T130000
DTSTAMP:20260430T232845
CREATED:20240227T112413Z
LAST-MODIFIED:20240227T112426Z
UID:10002877-1702036800-1702040400@cmsa.fas.harvard.edu
SUMMARY:Open Problems in Physics and Novel Solutions from Math
DESCRIPTION:Member Seminar \nSpeaker: Juven Wang \nTitle: Open Problems in Physics and Novel Solutions from Math \n  \nAbstract: (1) How do neutrinos obtain tiny mass and oscillate between e\, \mu\, \tau three flavors? What consists of Dark Matter? What causes leptogenesis and baryogenesis? \n(2) Why the Parity Symmetry is violated in the weak interaction? How do we quantum mechanically regularize and numerically simulate the Standard Model (chiral fermion/gauge theory) on the lattice in 3+1 spacetime dimensions? \n(3) Strong CP problem: Why is the neutron electric dipole moment nearly zero and QCD respects the CP = T symmetry? \n(4) Family/Generation problem: Why are there three families/generations of quarks and leptons? \nIn my talk\, I will sketch and propose novel solutions to these challenging open problems in physics based on my own work (available on arXiv\, some jointly with my collaborators). \nI will show that the eclectic cross-disciplinary fertilization of ideas between the Math-Physics geometry and topology\, Quantum Condensed Matter\, and High-Energy Physics (theory\, pheno\, lattice) can help solving these big problems. \nThe (1) answer relates to Ultra Unification: a Z_{16} class Atiyah-Patodi-Singer eta invariant (Baryon – Lepton)-protected topological superconductor and a symmetry-extended anomalous topological quantum field theory. \nThe (2) and (3) answers relate to a trivial cobordism class and Symmetric Mass Generation\, and disordering and removing the Pecci-Quinn axions. \nThe (4) answer has to do with the Hirzebruch signature and Atiyah-Singer index theorem\, gravitational Chern-Simons theory\, and 3 E8 quantum Hall states. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-12823/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231201T120000
DTEND;TZID=America/New_York:20231201T130000
DTSTAMP:20260430T232845
CREATED:20240227T112716Z
LAST-MODIFIED:20240227T112731Z
UID:10002878-1701432000-1701435600@cmsa.fas.harvard.edu
SUMMARY:An introduction to mixture of experts in deep learning
DESCRIPTION:Member Seminar \nSpeaker: Samy Jelassi \nTitle: An introduction to mixture of experts in deep learning \nAbstract: Scale has opened new frontiers in natural language processing – but at a high cost. Mixture-of-Experts (MoE) have been proposed as a path to even larger and more capable language models. They select different parameters for each incoming example. By doing so\, the parameter count is decoupled from the compute per example leading to very large\, but efficient models. In this talk\, I will review the concept of mixture of experts\, provide a basic description of the Switch Transformers model\, characterize some of their behaviors and conclude by highlighting some open problems in the field. This talk is mainly based on the following papers: https://arxiv.org/pdf/2101.03961.pdf\, https://arxiv.org/pdf/2209.01667.pdf .
URL:https://cmsa.fas.harvard.edu/event/member-seminar-12123/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231117T120000
DTEND;TZID=America/New_York:20231117T130000
DTSTAMP:20260430T232845
CREATED:20240227T113236Z
LAST-MODIFIED:20240227T113251Z
UID:10002879-1700222400-1700226000@cmsa.fas.harvard.edu
SUMMARY:A quasi-local mass in general relativity
DESCRIPTION:Member Seminar \nSpeaker: Aghil Alaee \nTitle: A quasi-local mass in general relativity \nAbstract: One of the fundamental open problems in geometric analysis and mathematical relativity is constructing a (universal) energy/mass quantity to compute the energy/mass of a finite region of spacetime\, which can include a star\, black hole\, or galaxy. We define a new gauge-independent quasi-local mass and energy with respect to the Minkowski spacetime\, and show its relation to the Brown-York Hamilton-Jacobi analysis. A quasi-local proof of the positivity\, based on spacetime harmonic functions\, is given for admissible closed spacelike 2-surfaces which enclose an initial data set satisfying the dominant energy condition.  Rigidity is also established in that vanishing energy implies that the 2-surface arises from an embedding into Minkowski space\, and conversely\, the mass vanishes for any such surface. This is joint work with M. Khuri and S.T. Yau. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-111723/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231103T120000
DTEND;TZID=America/New_York:20231103T130000
DTSTAMP:20260430T232845
CREATED:20240227T113702Z
LAST-MODIFIED:20240227T113702Z
UID:10002880-1699012800-1699016400@cmsa.fas.harvard.edu
SUMMARY:Deformations of Landau-Ginzburg models and their fibers
DESCRIPTION:Member Seminar \nSpeaker: Zi Yang Kang \nTitle: Deformations of Landau-Ginzburg models and their fibers \nAbstract: In mirror symmetry\, the dual object to a Fano variety is a Landau-Ginzburg model. Broadly\, a Landau-Ginzburg model is quasi-projective variety Y with a superpotential function w\, but not all such pairs correspond to Fano varieties under mirror symmetry\, so a very natural question to ask is: Which Landau-Ginzburg models are mirror to Fano varieties? In this talk\, I will discuss a cohomological characterization of mirrors of (semi-)Fano varieties\, focusing on the case of threefolds. I’ll discuss how this characterization relates to the deformation and Hodge theory of (Y\,w)\, and in particular\, how the classification of (semi-)Fano threefolds is related to questions about moduli spaces of lattice polarized K3 surfaces.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-11323/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231027T120000
DTEND;TZID=America/New_York:20231027T130000
DTSTAMP:20260430T232845
CREATED:20240223T110834Z
LAST-MODIFIED:20240223T110834Z
UID:10002858-1698408000-1698411600@cmsa.fas.harvard.edu
SUMMARY:Extension of pluricanonical forms in positive and mixed characteristics
DESCRIPTION:Member Seminar \nSpeaker: Iacopo Brivio (CMSA) \nTitle: Extension of pluricanonical forms in positive and mixed characteristics \nAbstract: The geometry of a complex manifold $X$ is to a large extent determined by its pluricanonical forms\, i.e. global sections of $(\Omega^{\dim X}_X)^{\otimes m}$ for $m\geq 0$. A famous theorem of Siu states that when $X\to D$ is a smooth projective family of complex manifolds\, then every pluricanonical form on $X_0$ extends to the whole of $X$. Both this theorem and the tools used in its proof had a deep impact in higher dimensional birational geometry and moduli theory. In this talk I am going to give an overview of the extension problem for pluricanonical forms when $D$ is the spectrum of a positive or mixed characteristic discrete valuation ring. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-102723/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231020T120000
DTEND;TZID=America/New_York:20231020T130000
DTSTAMP:20260430T232845
CREATED:20240223T110405Z
LAST-MODIFIED:20240223T110405Z
UID:10002856-1697803200-1697806800@cmsa.fas.harvard.edu
SUMMARY:Black Holes as Quantum Systems
DESCRIPTION:Member Seminar \nSpeaker: Daniel Kapec (CMSA) \nTitle: Black Holes as Quantum Systems \nAbstract: To an outside observer\, a black hole appears to be an ordinary quantum mechanical system with finite entropy and highly chaotic internal dynamics. Nevertheless\, the low-temperature thermodynamics of the Kerr black hole presents several puzzles. For instance\, the leading order semiclassical approximation to the black hole density of states predicts a surprisingly large ground state degeneracy\, while poorly understood quantum corrections are known to become increasingly important at low temperatures. I will review the modern picture of black holes as quantum systems and then discuss a recent result on the leading correction to the low-temperature thermodynamics of the Kerr black hole that resolves many of the old puzzles. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-102023/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231013T120000
DTEND;TZID=America/New_York:20231013T130000
DTSTAMP:20260430T232845
CREATED:20240223T105131Z
LAST-MODIFIED:20240223T105527Z
UID:10002852-1697198400-1697202000@cmsa.fas.harvard.edu
SUMMARY:On the Breakdown of Einstein's Gravity
DESCRIPTION:Member Seminar \nSpeaker: Puskar Mondal (CMSA) \nTitle: On the Breakdown of Einstein’s Gravity \nAbstract: It is important to understand under which conditions\, the solutions of non-linear hyperbolic PDEs break down in finite time. In the context of Einstein’s gravity\, this is very closely tied to naked singularity formation and Penrose’s weak cosmic censorship conjecture. In this talk\, I will give sharp estimates on the relevant geometric entities that allow one to continue the solutions of Einstein’s equations indefinitely in the future in a ‘time’ direction without forming a naked singularity.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-101323/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20231006T120000
DTEND;TZID=America/New_York:20231006T130000
DTSTAMP:20260430T232845
CREATED:20240223T105546Z
LAST-MODIFIED:20240223T105621Z
UID:10002854-1696593600-1696597200@cmsa.fas.harvard.edu
SUMMARY:Random matrices and large deviations 
DESCRIPTION:Member Seminar \nSpeaker: Benjamin McKenna \nTitle: Random matrices and large deviations \nAbstract: We give a generalist overview of random matrices and their (a)typical behaviors. In recent years\, classical results have been complemented by a variety of new ones\, in both the math and physics literatures\, whose proofs leverage connections with special integrals over matrix groups. Some of these models exhibit interesting transition points\, whose motivating relationships to eigenvector (de)localization are not yet fully understood. Based on joint work with Jonathan Husson. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-10623/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230929T120000
DTEND;TZID=America/New_York:20230929T130000
DTSTAMP:20260430T232845
CREATED:20240223T112516Z
LAST-MODIFIED:20240223T112516Z
UID:10002863-1695988800-1695992400@cmsa.fas.harvard.edu
SUMMARY:Moduli of vector bundles on curve and semiorthogonal decomposition
DESCRIPTION:Member Seminar \nSpeaker: Kai Xu (CMSA) \nTitle: Moduli of vector bundles on curve and semiorthogonal decomposition \nAbstract: In this talk we construct semiorthogonal decompositions of moduli of vector bundles on a curve into its symmetric powers. The essential ingredients in the proof include Borel-Weil-Bott theory for loop groups\, derived Schur-Weyl duality for current groups and derived Θ-stratification. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-92923/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230922T120000
DTEND;TZID=America/New_York:20230922T130000
DTSTAMP:20260430T232845
CREATED:20240223T112106Z
LAST-MODIFIED:20240223T112106Z
UID:10002861-1695384000-1695387600@cmsa.fas.harvard.edu
SUMMARY:Modularity of Landau-Ginzburg Models
DESCRIPTION:Member Seminar \nSpeaker: Chuck Doran \nTitle: Modularity of Landau-Ginzburg Models \nAbstract:  Fano varieties are the basic building blocks of algebraic varieties.  Smooth Fano varieties have been classified in dimensions one (the projective line)\, two (del Pezzo surfaces)\, and three (Mori-Mukai classification).  What does Mirror Symmetry have to say about such classifications?  By studying the Landau-Ginzburg models mirror to smooth Fano threefolds we can transform the Mori-Mukai classification into an effective uniruledness result for moduli spaces of certain K3 and abelian surfaces.  This is joint work with Andrew Harder\, Ludmil Katzarkov\, Mikhail Ovcharenko\, and Victor Przjalkowski (arXiv:2307.15607). \n  \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-92223/
LOCATION:Common Room\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230915T120000
DTEND;TZID=America/New_York:20230915T130000
DTSTAMP:20260430T232845
CREATED:20240223T112851Z
LAST-MODIFIED:20240223T112851Z
UID:10002864-1694779200-1694782800@cmsa.fas.harvard.edu
SUMMARY:Quantum UV-IR map and curve counts in skeins
DESCRIPTION:Member Seminar \nSpeaker: Sunghyuk Park \nTitle: Quantum UV-IR map and curve counts in skeins \nAbstract: Quantum UV-IR map (a.k.a. q-nonabelianization map)\, introduced by Neitzke and Yan\, is a map from UV line defects in a 4d N=2 theory of class S to those of the IR. Mathematically\, it can be described as a map between skein modules and is a close cousin of quantum trace map of Bonahon and Wong. \nIn this talk\, I will discuss how quantum UV-IR map can be generalized to a map between HOMFLYPT skein modules\, using skein-valued curve counts of Ekholm and Shende.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-91523/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
END:VCALENDAR