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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230907T133000
DTEND;TZID=America/New_York:20230907T143000
DTSTAMP:20260501T121307
CREATED:20240223T110205Z
LAST-MODIFIED:20240223T110205Z
UID:10002855-1694093400-1694097000@cmsa.fas.harvard.edu
SUMMARY:Correlation decay for finite lattice gauge theories
DESCRIPTION:Probability Seminar \nSpeaker: Arka Adhikari (Stanford) \nTitle: Correlation decay for finite lattice gauge theories \nAbstract: In the setting of lattice gauge theories with finite (possibly non-Abelian) gauge groups at weak coupling\, we prove exponential decay of correlations for a wide class of gauge invariant functions\, which in particular includes arbitrary functions of Wilson loop observables. Based on joint work with Sky Cao. \n 
URL:https://cmsa.fas.harvard.edu/event/probability-9723/
LOCATION:Science Center 232\, Harvard Science Center\, 1 Oxford Street\, Cambridge MA 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-09.07.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230906T160000
DTEND;TZID=America/New_York:20230906T170000
DTSTAMP:20260501T121307
CREATED:20240223T110729Z
LAST-MODIFIED:20240223T110729Z
UID:10002857-1694016000-1694019600@cmsa.fas.harvard.edu
SUMMARY:Light cones for open quantum systems
DESCRIPTION:Probability Seminar \nSpeaker: Marius Lemm\, University of Tuebingen \nTitle: Light cones for open quantum systems\n\nAbstract: We consider non-relativistic Markovian open quantum dynamics in continuous space. We show that\, up to small probability tails\, the supports of quantum states propagate with finite speed in any finite-energy subspace. More precisely\, if the initial quantum state is localized in space\, then any finite-energy part of the solution of the von Neumann-Lindblad equation is approximately localized inside an energy-dependent light cone. We also obtain an explicit upper bound on the slope of this light cone (i.e.\, on the maximal speed). The general method can be used to derive propagation bounds for a variety of other quantum systems including Lieb-Robinson bounds for lattice bosons. Based on joint works with S. Breteaux\, J. Faupin\, D.H. Ou Yang\, I.M. Sigal\, and J. Zhang.\n 
URL:https://cmsa.fas.harvard.edu/event/probability-9623/
LOCATION:Science Center 232\, Harvard Science Center\, 1 Oxford Street\, Cambridge MA 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-09.06.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230511T133000
DTEND;TZID=America/New_York:20230511T143000
DTSTAMP:20260501T121307
CREATED:20230808T180145Z
LAST-MODIFIED:20240111T084858Z
UID:10001199-1683811800-1683815400@cmsa.fas.harvard.edu
SUMMARY:How do the eigenvalues of a large non-Hermitian random matrix behave?
DESCRIPTION:Probability Seminar \nSpeaker: Giorgio Cipolloni (Princeton) \nTitle: How do the eigenvalues of a large non-Hermitian random matrix behave? \nAbstract: We prove that the fluctuations of the eigenvalues converge to the Gaussian Free Field (GFF) on the unit disk. These fluctuations appear on a non-natural scale\, due to strong correlations between the eigenvalues. Then\, motivated by the long time behaviour of the ODE \dot{u}=Xu\, we give a precise estimate on the eigenvalue with the largest real part and on the spectral radius of X. \nLocation: Science Center Room 232
URL:https://cmsa.fas.harvard.edu/event/probability-51123/
LOCATION:Harvard Science Center\, 1 Oxford Street\, Cambridge\, MA\, 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-05.11.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230503T153000
DTEND;TZID=America/New_York:20230503T163000
DTSTAMP:20260501T121307
CREATED:20230808T175916Z
LAST-MODIFIED:20240111T083748Z
UID:10001198-1683127800-1683131400@cmsa.fas.harvard.edu
SUMMARY:Random Neural Networks
DESCRIPTION:Probability Seminar \nSpeaker: Boris Hanin (Princeton)\n\nTitle: Random Neural Networks \nAbstract: Fully connected neural networks are described two by structural parameters: a depth L and a width N. In this talk\, I will present results and open questions about the asymptotic analysis of such networks with random weights and biases in the regime where N (and potentially L) are large. The first set of results are for deep linear networks\, which are simply products of L random matrices of size N x N. I’ll explain how the setting where the ratio L / N is fixed with both N and L large reveals a number of phenomena not present when only one of them is large. I will then state several results about non-linear networks in which this depth-to-width ratio L / N again plays a crucial role and gives an effective notion of depth for a random neural network.
URL:https://cmsa.fas.harvard.edu/event/probability-5323/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-05.03.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230426T153000
DTEND;TZID=America/New_York:20230426T163000
DTSTAMP:20260501T121307
CREATED:20230808T175545Z
LAST-MODIFIED:20240111T083026Z
UID:10001197-1682523000-1682526600@cmsa.fas.harvard.edu
SUMMARY:Boundary current fluctuations for the half space ASEP
DESCRIPTION:Probability Seminar \nSpeaker: Jimmy He (MIT) \nTitle: Boundary current fluctuations for the half space ASEP \nAbstract: The half space asymmetric simple exclusion process (ASEP) is an interacting particle system on the half line\, with particles allowed to enter/exit at the boundary. I will discuss recent work on understanding fluctuations for the number of particles in the half space ASEP started with no particles\, which exhibits the Baik-Rains phase transition between GSE\, GOE\, and Gaussian fluctuations as the boundary rates vary. As part of the proof\, we find new distributional identities relating this system to two other models\, the half space Hall-Littlewood process\, and the free boundary Schur process\, which allows exact formulas to be computed.
URL:https://cmsa.fas.harvard.edu/event/probability-42623/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-04.26.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230419T153000
DTEND;TZID=America/New_York:20230419T163000
DTSTAMP:20260501T121307
CREATED:20230808T175217Z
LAST-MODIFIED:20240111T082259Z
UID:10001196-1681918200-1681921800@cmsa.fas.harvard.edu
SUMMARY:Diagonalizing Transition Matrices of Card Shuffles
DESCRIPTION:Probability Seminar \nSpeaker: Evita Nestoridi (Stonybrook)\n\nTitle: Diagonalizing Transition Matrices of Card Shuffles \nAbstract: In their seminal work\, Diaconis and Shahshahani used representation theory of the symmetric group to diagonalize the transition matrix of random transpositions. More recently\, Dieker and Saliola introduced another technique to diagonalize the random-to-random card shuffle. In this talk we will discuss connections between these techniques as well as application to card shuffling.
URL:https://cmsa.fas.harvard.edu/event/probability-41923/
LOCATION:Science Center 232\, Harvard Science Center\, 1 Oxford Street\, Cambridge MA 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-04.19.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230412T153000
DTEND;TZID=America/New_York:20230412T163000
DTSTAMP:20260501T121307
CREATED:20230808T174934Z
LAST-MODIFIED:20240228T094844Z
UID:10001195-1681313400-1681317000@cmsa.fas.harvard.edu
SUMMARY:Large deviations of Selberg’s central limit theorem
DESCRIPTION:Probability Seminar \n\nSpeaker: Emma Bailey (CUNY) \nTitle: Large deviations of Selberg’s central limit theorem \nAbstract: Selberg’s CLT concerns the typical behaviour of the Riemann zeta function and shows that the random variable $\Re \log \zeta(1/2 + i t)$\, for a uniformly drawn $t$\, behaves as a Gaussian random variable with a particular variance.  It is natural to investigate how far into the tails this Gaussianity persists\, which is the topic of this work. There are also very close connections to similar problems in circular unitary ensemble characteristic polynomials.  It transpires that a `multiscale scheme’ can be applied to both situations to understand these questions of large deviations\, as well as certain maxima and moments. In this talk I will focus more on the techniques we apply to approach this problem and I will assume no number theoretic knowledge. This is joint work with Louis-Pierre Arguin.
URL:https://cmsa.fas.harvard.edu/event/probability-41223/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-04.12.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230410T150000
DTEND;TZID=America/New_York:20230410T160000
DTSTAMP:20260501T121307
CREATED:20230808T174720Z
LAST-MODIFIED:20240111T070433Z
UID:10001194-1681138800-1681142400@cmsa.fas.harvard.edu
SUMMARY:Localization for random band matrices
DESCRIPTION:Probability Seminar \n*Please note room change: Science Center 232* \n\nSpeaker: Ron Peled (Tel Aviv University) \nTitle: Localization for random band matrices \nAbstract: I will explain an approach via “an adaptive Mermin-Wagner style shift” which proves localization of N x N Gaussian random band matrices with band width W satisfying W << N^{1/4}. \nJoint work with Giorgio Cipolloni\, Jeffrey Schenker and Jacob Shapiro.
URL:https://cmsa.fas.harvard.edu/event/probability-41023/
LOCATION:Harvard Science Center\, 1 Oxford Street\, Cambridge\, MA\, 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-04.10.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230405T153000
DTEND;TZID=America/New_York:20230405T163000
DTSTAMP:20260501T121307
CREATED:20230807T173206Z
LAST-MODIFIED:20240111T070226Z
UID:10001193-1680708600-1680712200@cmsa.fas.harvard.edu
SUMMARY:Sampling from the SK and mixed p-spin measures with stochastic localization
DESCRIPTION:Probability Seminar \n\nSpeaker: Ahmed El Alaoui (Cornell) \nTitle: Sampling from the SK and mixed p-spin measures with stochastic localization \nAbstract: I will present an algorithm which efficiently samples from the Sherrington-Kirkpatrick (SK) measure with no external field at high temperature. The approach is based on the stochastic localization process of Eldan\, together with a subroutine for computing the mean vectors of a family of measures tilted by an appropriate external field. Conversely\, we show that no ‘stable’ algorithm can approximately sample from the SK measure at low temperature. Time permitting\, we discuss extensions to the p-spin model. This is based on a joint work with Andrea Montanari and Mark Sellke.
URL:https://cmsa.fas.harvard.edu/event/probability-4523/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-04.05.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230322T153000
DTEND;TZID=America/New_York:20230322T163000
DTSTAMP:20260501T121307
CREATED:20230807T172858Z
LAST-MODIFIED:20240215T105007Z
UID:10001192-1679499000-1679502600@cmsa.fas.harvard.edu
SUMMARY:Some rigorous results on the Lévy spin glass model
DESCRIPTION:Probability Seminar \nSpeaker: Wei-Kuo Chen (Minnesota)\n\nTitle: Some rigorous results on the Lévy spin glass model \nAbstract: The Lévy spin glass model\, proposed by Cizeau-Bouchaud\, is a mean-field model defined on a fully connected graph\, where the spin interactions are formulated through a power-law distribution. This model is well-motivated from the study of the experimental metallic spin glasses. It is also expected to bridge between some mean-field and diluted models. In this talk\, we will discuss some recent progress on the Lévy model including its high temperature behavior and the existence and variational expression for the limiting free energy. Based on a joint work with Heejune Kim and Arnab Sen.
URL:https://cmsa.fas.harvard.edu/event/probability-32223/
LOCATION:Virtual
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-03.22.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230309T110000
DTEND;TZID=America/New_York:20230309T120000
DTSTAMP:20260501T121307
CREATED:20230807T171904Z
LAST-MODIFIED:20240215T105139Z
UID:10001191-1678359600-1678363200@cmsa.fas.harvard.edu
SUMMARY:On the free energy of spin glasses with multiple types
DESCRIPTION:Probability Seminar \n\nSpeaker: Jean-Christophe Mourrat (ENS Lyon) \nTitle: On the free energy of spin glasses with multiple types \nAbstract: In the simplest spin-glass model\, due to Sherrington and Kirkpatrick\, the energy function involves interaction terms between all pairs of spins. A bipartite version of this model can be obtained by splitting the spins into two groups\, which we can visualize as forming two layers\, and by keeping only interaction terms that go from one to the other layer. For this and other models that incorporate a finite number of types of spins\, the asymptotic behavior of the free energy remains mysterious (at least from the mathematical point of view). I will present the difficulties arising there\, and some partial progress.
URL:https://cmsa.fas.harvard.edu/event/probability-3923/
LOCATION:Virtual
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-03.09.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230222T153000
DTEND;TZID=America/New_York:20230222T163000
DTSTAMP:20260501T121307
CREATED:20230807T171541Z
LAST-MODIFIED:20240111T065432Z
UID:10001190-1677079800-1677083400@cmsa.fas.harvard.edu
SUMMARY:Thresholds for edge colorings
DESCRIPTION:Probability Seminar \nSpeaker: Vishesh Jain (University of Illinois Chicago)\n\nTitle: Thresholds for edge colorings\n\nAbstract: We show that if each edge of the complete bipartite graph K_{n\,n} is given a random list of C(\log n) colors from [n]\, then with high probability\, there is a proper edge coloring where the color of each edge comes from the corresponding list. We also prove analogous results for Latin squares and Steiner triple systems. This resolves several related conjectures of Johansson\, Luria-Simkin\, Casselgren-Häggkvist\, Simkin\, and Kang-Kelly-Kühn-Methuku-Osthus. I will discuss some of the main ingredients which go into the proof: the Kahn-Kalai conjecture\, absorption\, and the Lovasz Local Lemma distribution. Based on joint work with Huy Tuan Pham.
URL:https://cmsa.fas.harvard.edu/event/probability-22223/
LOCATION:Virtual
CATEGORIES:Probability Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230215T153000
DTEND;TZID=America/New_York:20230215T163000
DTSTAMP:20260501T121307
CREATED:20230807T170715Z
LAST-MODIFIED:20240228T100906Z
UID:10001189-1676475000-1676478600@cmsa.fas.harvard.edu
SUMMARY:Manifold Fitting: An Invitation to Statistics
DESCRIPTION:Probability Seminar \nSpeaker: Zhigang Yao (Harvard CMSA/National University of Singapore)\n\n\nTitle: Manifold Fitting: An Invitation to Statistics \nAbstract: This manifold fitting problem can go back to H. Whitney’s work in the early 1930s (Whitney (1992))\, and finally has been answered in recent years by C. Fefferman’s works (Fefferman\, 2006\, 2005). The solution to the Whitney extension problem leads to new insights for data interpolation and inspires the formulation of the Geometric Whitney Problems (Fefferman et al. (2020\, 2021a)): Assume that we are given a set $Y \subset \mathbb{R}^D$. When can we construct a smooth $d$-dimensional submanifold $\widehat{M} \subset \mathbb{R}^D$ to approximate $Y$\, and how well can $\widehat{M}$ estimate $Y$ in terms of distance and smoothness? To address these problems\, various mathematical approaches have been proposed (see Fefferman et al. (2016\, 2018\, 2021b)). However\, many of these methods rely on restrictive assumptions\, making extending them to efficient and workable algorithms challenging. As the manifold hypothesis (non-Euclidean structure exploration) continues to be a foundational element in statistics\, the manifold fitting Problem\, merits further exploration and discussion within the modern statistical community. The talk will be partially based on a recent work Yao and Xia (2019) along with some on-going progress. Relevant reference: https://arxiv.org/abs/1909.10228
URL:https://cmsa.fas.harvard.edu/event/probability-21523/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-02.15.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20230208T153000
DTEND;TZID=America/New_York:20230208T163000
DTSTAMP:20260501T121307
CREATED:20230807T170441Z
LAST-MODIFIED:20240228T112614Z
UID:10001188-1675870200-1675873800@cmsa.fas.harvard.edu
SUMMARY:Bakry-Emery theory and renormalisation
DESCRIPTION:Probability Seminar \nSpeaker: Roland Bauerschmidt (Cambridge)\n\nTitle: Bakry-Emery theory and renormalisation \nAbstract: I will discuss an approach to log-Sobolev inequalities that\ncombines the Bakry-Emery theory with renormalisation and present several\napplications. These include log-Sobolev inequalities with polynomial\ndependence for critical Ising models on Z^d when d>4 and singular SPDEs\nwith uniform dependence of the log-Sobolev constant on both the\nregularisation and the volume. The talk is based on joint works with\nThierry Bodineau and Benoit Dagallier.
URL:https://cmsa.fas.harvard.edu/event/probability-2823/
LOCATION:Hybrid
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-02.08.23.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221207T153000
DTEND;TZID=America/New_York:20221207T163000
DTSTAMP:20260501T121307
CREATED:20230807T165823Z
LAST-MODIFIED:20240110T091938Z
UID:10001187-1670427000-1670430600@cmsa.fas.harvard.edu
SUMMARY:Fourier quasicrystals and stable polynomials
DESCRIPTION:Probability Seminar \nNote location change: Science Center Room 300H \nSpeaker: Lior Alon (MIT) \nTitle: Fourier quasicrystals and stable polynomials \nAbstract: The Poisson summation formula says that the countable sum of exp(int)\, over all integers n\, vanishes as long as t is not an integer multiple of 2 pi. Can we find a non-periodic discrete set A\, such that the sum of exp(iat)\, over a in A\, vanishes for all t outside of a discrete set? The surprising answer is yes. Yves Meyer called the atomic measure supported on such a set a crystalline measure. Crystalline measures provide another surprising connection between physics (quasicrystals) and number theory (the zeros of the Zeta and L functions under GRH). A recent work of Pavel Kurasov and Peter Sarnak provided a construction of crystalline measures with ‘good’ convergence (Fourier quasicrystals) using stable polynomials\, a family of multivariate polynomials that were previously used in proving the Lee-Yang circle theorem and the Kadison-Singer conjecture. After providing the needed background\, I will discuss a recent work in progress with Cynthia Vinzant on the classification of these Kurasov-Sarnak measures and their supporting sets. We prove that these sets have well-defined gap distributions. We show that each Kurasov-Sarnak measure decomposes according to the irreducible decomposition of its associated polynomial\, and the measures associated with each irreducible factor is either supported on an arithmetic progression\, or its support has a bounded intersection with any arithmetic progression. Finally\, we construct random Kurasov-Sarnak measures with gap distribution as close as we want to the eigenvalues spacing of a random unitary matrix. \nBased on joint work with Pravesh Kothari.
URL:https://cmsa.fas.harvard.edu/event/probability-12722/
LOCATION:Harvard Science Center\, 1 Oxford Street\, Cambridge\, MA\, 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-12.07.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221202T110000
DTEND;TZID=America/New_York:20221202T120000
DTSTAMP:20260501T121307
CREATED:20230817T164654Z
LAST-MODIFIED:20240229T111029Z
UID:10001230-1669978800-1669982400@cmsa.fas.harvard.edu
SUMMARY:Compactness and Anticompactness Principles in Set Theory
DESCRIPTION:Member Seminar \nSpeaker: Alejandro Poveda \nTitle: Compactness and Anticompactness Principles in Set Theory \nAbstract: Several fundamental properties in Topology\, Algebra or Logic are expressed in terms of Compactness Principles.For instance\, a natural algebraic question is the following: Suppose that G is an Abelian group whose all small subgroups are free – Is the group G free? If the answer is affirmative one says that compactness holds; otherwise\, we say that compactness fails. Loosely speaking\, a compactness principle is anything that fits the following slogan: Suppose that M is a mathematical structure (a group\, a topological space\, etc) such that all of its small substructures N have certain property $\varphi$; then the ambient structure M has property $\varphi$\, as well. Oftentimes when these questions are posed for infinite sets the problem becomes purely set-theoretical and axiom-sensitive. In this talk I will survey the most paradigmatic instances of compactness and present some related results of mine. If time permits\, I will hint the proof of a recent result (joint with Rinot and Sinapova) showing that stationary reflection and the failure of the Singular Cardinal Hypothesis can co-exist. These are instances of two antagonist set-theoretic principles: the first is a compactness principle while the second is an anti-compactness one. This result solves a question by M. Magidor from 1982.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-12222/
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:20221130T150000
DTEND;TZID=America/New_York:20221130T160000
DTSTAMP:20260501T121307
CREATED:20230807T165526Z
LAST-MODIFIED:20240110T091213Z
UID:10001186-1669820400-1669824000@cmsa.fas.harvard.edu
SUMMARY:Lipschitz properties of transport maps under a log-Lipschitz condition
DESCRIPTION:Probability Seminar \n\nLocation: Room 109\, Harvard Science Center\, 1 Oxford Street\, Cambridge MA 02138\nSpeaker: Dan Mikulincer (MIT) \n\n\nTitle: Lipschitz properties of transport maps under a log-Lipschitz condition \nAbstract: Consider the problem of realizing a target probability measure as a push forward\, by a transport map\, of a given source measure. Typically one thinks about the target measure as being ‘complicated’ while the source is simpler and often more structured. In such a setting\, for applications\, it is desirable to find Lipschitz transport maps which afford the transfer of analytic properties from the source to the target. The talk will focus on Lipschitz regularity when the target measure satisfies a log-Lipschitz condition. \nI will present a construction of a transport map\, constructed infinitesimally along the Langevin flow\, and explain how to analyze its Lipschitz constant. The analysis of this map leads to several new results which apply both to Euclidean spaces and manifolds\, and which\, at the moment\, seem to be out of reach of the classically studied optimal transport theory. \nJoint work with Max Fathi and Yair Shenfeld.
URL:https://cmsa.fas.harvard.edu/event/probability-113022/
LOCATION:Harvard Science Center\, 1 Oxford Street\, Cambridge\, MA\, 02138
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-11.30.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221118T110000
DTEND;TZID=America/New_York:20221118T120000
DTSTAMP:20260501T121307
CREATED:20230809T111725Z
LAST-MODIFIED:20240209T052933Z
UID:10001229-1668769200-1668772800@cmsa.fas.harvard.edu
SUMMARY:Light states in the interior of CY moduli spaces
DESCRIPTION:Member Seminar \nSpeaker: Damian van de Heisteeg \nTitle: Light states in the interior of CY moduli spaces \nAbstract: In string theory one finds that states become massless as one approaches boundaries in Calabi-Yau moduli spaces. In this talk we look in the opposite direction\, that is\, we search for points where the mass gap for these light states is maximized — the so-called desert. In explicit examples we identify these desert points\, and find that they correspond to special points in the moduli space of the CY\, such as orbifold points and rank two attractors.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-111822/
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-11.18.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221116T153000
DTEND;TZID=America/New_York:20221116T163000
DTSTAMP:20260501T121307
CREATED:20230802T172705Z
LAST-MODIFIED:20240110T084219Z
UID:10001185-1668612600-1668616200@cmsa.fas.harvard.edu
SUMMARY:Outlier-Robust Algorithms for Clustering Non-Spherical Mixtures
DESCRIPTION:Probability Seminar \n\nSpeaker: Ainesh Bakshi (MIT) \nTitle: Outlier-Robust Algorithms for Clustering Non-Spherical Mixtures \nAbstract: In this talk\, we describe the first polynomial time algorithm for robustly clustering a mixture of statistically-separated\, high-dimensional Gaussians. Prior to our work this question was open even in the special case of 2 components in the mixture. Our main conceptual contribution is distilling analytic properties of distributions\, namely hyper-contractivity of degree-two polynomials and anti-concentration of linear projections\, which are necessary and sufficient for clustering.
URL:https://cmsa.fas.harvard.edu/event/probability-111622/
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-11.16.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221111T110000
DTEND;TZID=America/New_York:20221111T120000
DTSTAMP:20260501T121307
CREATED:20230809T111328Z
LAST-MODIFIED:20240209T052938Z
UID:10001228-1668164400-1668168000@cmsa.fas.harvard.edu
SUMMARY:Quantum trace and length conjecture for hyperbolic knot
DESCRIPTION:Member Seminar \nSpeaker: Mauricio Romo \nTitle: Quantum trace and length conjecture for hyperbolic knot \nAbstract: I will define the quantum trace map for an ideally triangulated hyperbolic knot complement on S^3. This map assigns an operator to each element L of  the Kauffman Skein module of knot complement.  Motivated by an interpretation of this operator in the context of SL(2\,C) Chern-Simons theory\, one can formulate a ‘length conjecture’ for the hyperbolic length of L.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-111122/
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:20221109T153000
DTEND;TZID=America/New_York:20221109T163000
DTSTAMP:20260501T121307
CREATED:20230802T172421Z
LAST-MODIFIED:20240110T075312Z
UID:10001184-1668007800-1668011400@cmsa.fas.harvard.edu
SUMMARY:Liouville quantum gravity from random matrix dynamics
DESCRIPTION:Probability Seminar \nSpeaker: Hugo Falconet (Courant Institute\, NYU) \nTitle: Liouville quantum gravity from random matrix dynamics \nAbstract: The Liouville quantum gravity measure is a properly renormalized exponential of the 2d GFF. In this talk\, I will explain how it appears as a limit of natural random matrix dynamics: if (U_t) is a Brownian motion on the unitary group at equilibrium\, then the measures $|det(U_t – e^{i theta}|^gamma dt dtheta$ converge to the 2d LQG measure with parameter $gamma$\, in the limit of large dimension. This extends results from Webb\, Nikula and Saksman for fixed time. The proof relies on a new method for Fisher-Hartwig asymptotics of Toeplitz determinants with real symbols\, which extends to multi-time settings. I will explain this method and how to obtain multi-time loop equations by stochastic analysis on Lie groups. \nBased on a joint work with Paul Bourgade. \n 
URL:https://cmsa.fas.harvard.edu/event/probability-11922/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Probability Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-Probability-Seminar-11.09.22-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221028T110000
DTEND;TZID=America/New_York:20221028T120000
DTSTAMP:20260501T121307
CREATED:20230809T110603Z
LAST-MODIFIED:20240301T080243Z
UID:10001227-1666954800-1666958400@cmsa.fas.harvard.edu
SUMMARY:Some non-concave dynamic optimization problems in finance
DESCRIPTION:Member Seminar \nSpeaker: Shuaijie Qian (Harvard CMSA) \nTitle: Some non-concave dynamic optimization problems in finance \nAbstract: Non-concave dynamic optimization problems appear in many areas of finance and economics. Most of existing literature solves these problems using the concavification principle\, and derives equivalent\, concave optimization problems whose value functions are still concave. In this talk\, I will present our recent work on some non-concave dynamic optimization problems\, where the concavification principle may not hold and the resulting value function is indeed non-concave. \nThe first work is about the portfolio selection model with capital gains tax and a bitcoin mining model with exit options and technology innovation\, where the average tax basis and the average mining cost serves as an approximation\, respectively. This approximation results in a non-concave value function\, and the associated HJB equation problem turns out to admit infinitely many solutions. We show that the value function is the minimal (viscosity) solution of the HJB equation problem. Moreover\, the penalty method still works and converges to the value function. \nThe second work is about a non-concave utility maximization problem with portfolio constraints. We find that adding bounded portfolio constraints\, which makes the concavification principle invalid\, can significantly affect economic insights in the existing literature. As the resulting value function is likely discontinuous\, we introduce a new definition of viscosity solution\, prove the corresponding comparison principle\, and show that a monotone\, stable\, and consistent finite difference scheme converges to the solution of the utility maximization problem. \n 
URL:https://cmsa.fas.harvard.edu/event/member-seminar-title-tba-6/
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:20221021T110000
DTEND;TZID=America/New_York:20221021T120000
DTSTAMP:20260501T121307
CREATED:20230809T110107Z
LAST-MODIFIED:20240301T080144Z
UID:10001226-1666350000-1666353600@cmsa.fas.harvard.edu
SUMMARY:Explicit Ramsey Graphs and Two Source Extractors
DESCRIPTION:Speaker: David Zuckerman\, Harvard CMSA/University of Texas at Austin \nTitle: Explicit Ramsey Graphs and Two Source Extractors \nAbstract: Ramsey showed that any graph on N nodes contains a clique or independent set of size (log N)/2.  Erdos showed that there exist graphs on N nodes with no clique or independent set of size 2 log N\, and asked for an explicit construction of such graphs.  This turns out to relate to the question of extracting high-quality randomness from two independent low-quality sources.  I’ll explain this connection and our recent exponential improvement in constructing two-source extractors.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-title-tba-5/
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-10.21.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221014T110000
DTEND;TZID=America/New_York:20221014T120000
DTSTAMP:20260501T121307
CREATED:20240214T103536Z
LAST-MODIFIED:20240301T081027Z
UID:10002676-1665745200-1665748800@cmsa.fas.harvard.edu
SUMMARY:Quantum magnet chains and Kashiwara crystals
DESCRIPTION:Speaker: Leonid Rybnikov\, Harvard CMSA/National Research University Higher School of Economics \nTitle: Quantum magnet chains and Kashiwara crystals \nAbstract: Solutions of the algebraic Bethe ansatz for quantum magnet chains are\, generally\, multivalued functions of the parameters of the integrable system. I will explain how to compute some monodromies of solutions of Bethe ansatz for the Gaudin magnet chain. Namely\, the Bethe eigenvectors in the Gaudin model can be regarded as a covering of the Deligne-Mumford moduli space of stable rational curves\, which is unramified over the real locus of the Deligne-Mumford space. The monodromy action of the fundamental group of this space (called cactus group) on the eigenlines can be described very explicitly in purely combinatorial terms of Kashiwara crystals — i.e. combinatorial objects modeling the tensor category of finite-dimensional representations of a semisimple Lie algebra g. More specifically\, this monodromy action is naturally equivalent to the action of the same group by commutors (i.e. combinatorial analog of a braiding) on a tensor product of Kashiwara crystals. This is joint work with Iva Halacheva\, Joel Kamnitzer\, and Alex Weekes.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-101422/
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-10.14.22.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20221007T110000
DTEND;TZID=America/New_York:20221007T120000
DTSTAMP:20260501T121307
CREATED:20240214T105028Z
LAST-MODIFIED:20240301T081713Z
UID:10002681-1665140400-1665144000@cmsa.fas.harvard.edu
SUMMARY:Principal flow\, sub-manifold and boundary
DESCRIPTION:Member Seminar  \nSpeaker: Zhigang Yao \nTitle: Principal flow\, sub-manifold and boundary \nAbstract: While classical statistics has dealt with observations which are real numbers or elements of a real vector space\, nowadays many statistical problems of high interest in the sciences deal with the analysis of data which consist of more complex objects\, taking values in spaces which are naturally not (Euclidean) vector spaces but which still feature some geometric structure. I will discuss the problem of finding principal components to the multivariate datasets\, that lie on an embedded nonlinear Riemannian manifold within the higher-dimensional space. The aim is to extend the geometric interpretation of PCA\, while being able to capture the non-geodesic form of variation in the data. I will introduce the concept of a principal sub-manifold\, a manifold passing through the center of the data\, and at any point on the manifold extending in the direction of highest variation in the space spanned by the eigenvectors of the local tangent space PCA. We show the principal sub-manifold yields the usual principal components in Euclidean space. We illustrate how to find\, use and interpret the principal sub-manifold\, by which a principal boundary can be further defined for data sets on manifolds.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-10722/
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:20220930T110000
DTEND;TZID=America/New_York:20220930T120000
DTSTAMP:20260501T121307
CREATED:20240214T105247Z
LAST-MODIFIED:20240301T081921Z
UID:10002683-1664535600-1664539200@cmsa.fas.harvard.edu
SUMMARY:Kahler geometry in twisted materials
DESCRIPTION:Member Seminar \nSpeaker: Jie Wang \nTitle: Kahler geometry in twisted materials \nAbstract: Flatbands are versatile platform for realizing exotic quantum phases due to the enhanced interactions. The canonical example is Landau level where fractional quantum Hall physics exists. Although interaction is strong\, the fractional quantum Hall effect is relatively well understood thanks to its model wavefunction\, exact parent Hamiltonian\, conformal field theory analogous and other exact aspects. In generic flatbands\, the interacting physics is controlled by the interplay between the interaction scale and intrinsic quantum geometries\, in particular the Berry curvature and the Fubini-Study metric\, which are in general spatially non-uniform. It is commonly believed that the non-uniform geometries destroy these exact properties of fractional quantum Hall physics\, making many-body states less stable in flatbands. \nIn this talk\, I will disprove this common belief by showing a large family of flatbands (ideal flatbands) where quantum geometries can be highly non-uniform\, but still exhibit exact properties such as model wavefunctions\, density algebra\, exact parent Hamiltonians. I will discuss both the theory of ideal flatband\, its experimental realization in Dirac materials as well as implications.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-93022/
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:20220923T110000
DTEND;TZID=America/New_York:20220923T120000
DTSTAMP:20260501T121307
CREATED:20240214T105452Z
LAST-MODIFIED:20240301T083553Z
UID:10002685-1663930800-1663934400@cmsa.fas.harvard.edu
SUMMARY:Random determinants\, the elastic manifold\, and landscape complexity beyond invariance
DESCRIPTION:Member Seminar \nSpeaker: Ben McKenna \nTitle: Random determinants\, the elastic manifold\, and landscape complexity beyond invariance \nAbstract: The Kac-Rice formula allows one to study the complexity of high-dimensional Gaussian random functions (meaning asymptotic counts of critical points) via the determinants of large random matrices. We present new results on determinant asymptotics for non-invariant random matrices\, and use them to compute the (annealed) complexity for several types of landscapes. We focus especially on the elastic manifold\, a classical disordered elastic system studied for example by Fisher (1986) in fixed dimension and by Mézard and Parisi (1992) in the high-dimensional limit. We confirm recent formulas of Fyodorov and Le Doussal (2020) on the model in the Mézard-Parisi setting\, identifying the boundary between simple and glassy phases. Joint work with Gérard Ben Arous and Paul Bourgade.
URL:https://cmsa.fas.harvard.edu/event/member-seminar-title-tba/
LOCATION:CMSA Room G10\, CMSA\, 20 Garden Street\, Cambridge\, MA\, 02138\, United States
CATEGORIES:Member Seminar
END:VEVENT
END:VCALENDAR