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DTSTART:20210314T070000
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DTSTART:20211107T060000
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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210426T100000
DTEND;TZID=America/New_York:20210426T110000
DTSTAMP:20260506T163757
CREATED:20240126T064113Z
LAST-MODIFIED:20240126T064113Z
UID:10001381-1619431200-1619434800@cmsa.fas.harvard.edu
SUMMARY:4/26/2021 Math Physics Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-26-2021-math-physics-seminar/
LOCATION:Virtual
CATEGORIES:Mathematical Physics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210423T160000
DTEND;TZID=America/New_York:20210423T183000
DTSTAMP:20260506T163757
CREATED:20230707T172354Z
LAST-MODIFIED:20250328T185338Z
UID:10000912-1619193600-1619202600@cmsa.fas.harvard.edu
SUMMARY:CMSA Math-Science Literature Lecture: Indistinguishability Obfuscation: How to Hide Secrets within Software
DESCRIPTION:Amit Sahai  (UCLA) \nTitle: Indistinguishability Obfuscation: How to Hide Secrets within Software \nAbstract: At least since the initial public proposal of public-key cryptography based on computational hardness conjectures (Diffie and Hellman\, 1976)\, cryptographers have contemplated the possibility of a “one-way compiler” that translates computer programs into “incomprehensible” but equivalent forms. And yet\, the search for such a “one-way compiler” remained elusive for decades. \nIn this talk\, we look back at our community’s attempts to formalize the notion of such a compiler\, culminating in our 2001 work with Barak\, Goldreich\, Impagliazzo\, Rudich\, Vadhan\, and Yang\, which proposed the notion of indistinguishability obfuscation (iO). Roughly speaking\, iO requires that the compiled versions of any two equivalent programs (with the same size and running time) be indistinguishable to any efficient adversary. Leveraging the notion of punctured programming\, introduced in our work with Waters in 2013\, well over a hundred papers have explored the remarkable power of iO. \nWe’ll then discuss the intense effort that recently culminated in our 2020 work with Jain and Lin\, finally showing how to construct iO in such a way that\, for the first time\, we can prove the security of our iO scheme based on well-studied computational hardness conjectures in cryptography. \nTalk chair: Sergiy Verstyuk \nVideo
URL:https://cmsa.fas.harvard.edu/event/cmsa-math-science-literature-lecture_sahai/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/Lecture_Sahai-pdf.jpeg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210422T103000
DTEND;TZID=America/New_York:20210422T120000
DTSTAMP:20260506T163757
CREATED:20240126T064439Z
LAST-MODIFIED:20240126T064439Z
UID:10001383-1619087400-1619092800@cmsa.fas.harvard.edu
SUMMARY:4/22/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-22-2021-quantum-matter-seminar/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210422T090000
DTEND;TZID=America/New_York:20210422T100000
DTSTAMP:20260506T163757
CREATED:20240126T063818Z
LAST-MODIFIED:20240126T063818Z
UID:10001379-1619082000-1619085600@cmsa.fas.harvard.edu
SUMMARY:4/22/2021 Interdisciplinary Science Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-22-2021-interdisciplinary-science-seminar/
LOCATION:MA
CATEGORIES:Interdisciplinary Science Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210421T150000
DTEND;TZID=America/New_York:20210421T160000
DTSTAMP:20260506T163757
CREATED:20240126T065403Z
LAST-MODIFIED:20240515T192602Z
UID:10001388-1619017200-1619020800@cmsa.fas.harvard.edu
SUMMARY:Homotopy type theory and the quest for extensionality
DESCRIPTION:Speaker: Michael Shulman – Dept. of Mathematics\, University of San Diego \nTitle: Homotopy type theory and the quest for extensionality \nAbstract: Over the past decades\, dependent type theory has proven to be a powerful framework for verified software and formalized mathematics.  However\, its treatment of equality has always been somewhat uncomfortable.  Recently\, homotopy type theory has made progress towards a more useful notion of equality\, which natively implements both isomorphism-invariance in mathematics and representation-independence in programming. This progress is based on ideas from abstract homotopy theory and higher category theory\, and with the development of cubical type theories it can be implemented as a true programming language.  In this talk\, I will survey these developments and their potential applications\, and suggest some directions for further improvement. \n 
URL:https://cmsa.fas.harvard.edu/event/4-21-2021-new-tech-in-math-seminar/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-New-Technologies-in-Mathematics-04.21.21.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210421T140000
DTEND;TZID=America/New_York:20210421T150000
DTSTAMP:20260506T163757
CREATED:20240126T072424Z
LAST-MODIFIED:20240126T072424Z
UID:10001393-1619013600-1619017200@cmsa.fas.harvard.edu
SUMMARY:4/21/2021 Random Matrix and Probability Theory Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-21-2021-random-matrix-and-probability-theory-seminar/
LOCATION:MA
CATEGORIES:Random Matrix & Probability Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210421T103000
DTEND;TZID=America/New_York:20210421T120000
DTSTAMP:20260506T163757
CREATED:20240126T063939Z
LAST-MODIFIED:20240126T063939Z
UID:10001380-1619001000-1619006400@cmsa.fas.harvard.edu
SUMMARY:4/21/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-21-2021-quantum-matter-seminar/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210420T090000
DTEND;TZID=America/New_York:20210420T103000
DTSTAMP:20260506T163757
CREATED:20230707T172100Z
LAST-MODIFIED:20250328T201355Z
UID:10000911-1618909200-1618914600@cmsa.fas.harvard.edu
SUMMARY:CMSA Math-Science Literature Lecture: The Atiyah-Singer Index Theorem
DESCRIPTION:Dan Freed (The University of Texas at Austin) \nTitle: The Atiyah-Singer Index Theorem \nAbstract: The story of the index theorem ties together the Gang of Four—Atiyah\, Bott\, Hirzebruch\, and Singer—and lies at the intersection of analysis\, geometry\, and topology. In the first part of the talk I will recount high points in the early developments. Then I turn to subsequent variations and applications. Throughout I emphasize the role of the Dirac operator. \nThis talk is part of a subprogram of the Mathematical Science Literature Lecture series\, a Memorial Conference for the founders of index theory: Atiyah\, Bott\, Hirzebruch and Singer. \nTalk chair: Cumrun Vafa \nVideo
URL:https://cmsa.fas.harvard.edu/event/cmsa-math-science-literature-lecture_freed/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Lecture_Freed-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210419T100000
DTEND;TZID=America/New_York:20210419T110000
DTSTAMP:20260506T163757
CREATED:20240126T065219Z
LAST-MODIFIED:20240126T065219Z
UID:10001387-1618826400-1618830000@cmsa.fas.harvard.edu
SUMMARY:4/19/2021 Mathematical Physics Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-19-2021-mathematical-physics-seminar/
LOCATION:Virtual
CATEGORIES:Mathematical Physics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210416T140000
DTEND;TZID=America/New_York:20210416T150000
DTSTAMP:20260506T163757
CREATED:20240126T064234Z
LAST-MODIFIED:20240126T064234Z
UID:10001382-1618581600-1618585200@cmsa.fas.harvard.edu
SUMMARY:4/16/2021 Random Matrix and Probability Theory Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-16-2021-random-matrix-and-probability-theory-seminar/
LOCATION:Virtual
CATEGORIES:Random Matrix & Probability Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210416T130000
DTEND;TZID=America/New_York:20210416T143000
DTSTAMP:20260506T163757
CREATED:20230707T171834Z
LAST-MODIFIED:20250328T201348Z
UID:10000910-1618578000-1618583400@cmsa.fas.harvard.edu
SUMMARY:CMSA Math-Science Literature Lecture: Deep Networks from First Principles
DESCRIPTION:Yi MaPhoto Copyright Noah Berger / 2019\n  \nYi Ma (University of California\, Berkeley) \nTitle: Deep Networks from First Principles \nAbstract: In this talk\, we offer an entirely “white box’’ interpretation of deep (convolution) networks from the perspective of data compression (and group invariance). In particular\, we show how modern deep layered architectures\, linear (convolution) operators and nonlinear activations\, and even all parameters can be derived from the principle of maximizing rate reduction (with group invariance). All layers\, operators\, and parameters of the network are explicitly constructed via forward propagation\, instead of learned via back propagation. All components of so-obtained network\, called ReduNet\, have precise optimization\, geometric\, and statistical interpretation. There are also several nice surprises from this principled approach: it reveals a fundamental tradeoff between invariance and sparsity for class separability; it reveals a fundamental connection between deep networks and Fourier transform for group invariance – the computational advantage in the spectral domain (why spiking neurons?); this approach also clarifies the mathematical role of forward propagation (optimization) and backward propagation (variation). In particular\, the so-obtained ReduNet is amenable to fine-tuning via both forward and backward (stochastic) propagation\, both for optimizing the same objective. This is joint work with students Yaodong Yu\, Ryan Chan\, Haozhi Qi of Berkeley\, Dr. Chong You now at Google Research\, and Professor John Wright of Columbia University. \nTalk chair: Harry Shum \nSlides | Video
URL:https://cmsa.fas.harvard.edu/event/cmsa-math-science-literature-lecture_ma/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/jpeg:https://cmsa.fas.harvard.edu/media/Lecture_Ma-1-pdf.jpeg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210415T113000
DTEND;TZID=America/New_York:20210415T123000
DTSTAMP:20260506T163757
CREATED:20240126T064814Z
LAST-MODIFIED:20240126T064814Z
UID:10001385-1618486200-1618489800@cmsa.fas.harvard.edu
SUMMARY:4/20/2021 Computer Science for Mathematicians
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-20-2021-computer-science-for-mathematicians/
LOCATION:MA
CATEGORIES:Computer Science for Mathematicians Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210415T103000
DTEND;TZID=America/New_York:20210415T120000
DTSTAMP:20260506T163757
CREATED:20240126T065533Z
LAST-MODIFIED:20240126T065533Z
UID:10001389-1618482600-1618488000@cmsa.fas.harvard.edu
SUMMARY:4/15/2021 Quantum Matter in Mathematics Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-15-2021-quantum-matter-in-mathematics-seminar/
LOCATION:MA
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210415T090000
DTEND;TZID=America/New_York:20210415T100000
DTSTAMP:20260506T163757
CREATED:20240126T065040Z
LAST-MODIFIED:20240126T065040Z
UID:10001386-1618477200-1618480800@cmsa.fas.harvard.edu
SUMMARY:4/15/2021 Interdisciplinary Science Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-15-2021-interdisciplinary-science-seminar/
LOCATION:Virtual
CATEGORIES:Interdisciplinary Science Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210414T150000
DTEND;TZID=America/New_York:20210414T160000
DTSTAMP:20260506T163757
CREATED:20240126T064644Z
LAST-MODIFIED:20240517T194855Z
UID:10001384-1618412400-1618416000@cmsa.fas.harvard.edu
SUMMARY:A Bayesian neural network predicts the dissolution of compact planetary systems
DESCRIPTION:Speaker: Miles Cranmer – Princeton University \nTitle: A Bayesian neural network predicts the dissolution of compact planetary systems \nAbstract: Despite over three hundred years of effort\, no solutions exist for predicting when a general planetary configuration will become unstable. I will discuss our deep learning architecture (arxiv:2101.04117) which pushes forward this problem for compact systems. While current machine learning algorithms in this area rely on scientist-derived instability metrics\, our new technique learns its own metrics from scratch\, enabled by a novel internal structure inspired from dynamics theory. The Bayesian neural network model can accurately predict not only if\, but also when a compact planetary system with three or more planets will go unstable. Our model\, trained directly from short N-body time series of raw orbital elements\, is more than two orders of magnitude more accurate at predicting instability times than analytical estimators\, while also reducing the bias of existing machine learning algorithms by nearly a factor of three. Despite being trained on three-planet configurations\, the model demonstrates robust generalization to five-planet systems\, even outperforming models designed for that specific set of integrations. I will also discuss some work on recovering symbolic representations of such models using arxiv:2006.11287.
URL:https://cmsa.fas.harvard.edu/event/4-14-2021-new-technologies-in-mathematics/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-New-Technologies-in-Mathematics-04.14.21.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210414T103000
DTEND;TZID=America/New_York:20210414T120000
DTSTAMP:20260506T163757
CREATED:20240126T065702Z
LAST-MODIFIED:20240126T065702Z
UID:10001390-1618396200-1618401600@cmsa.fas.harvard.edu
SUMMARY:4/14/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-14-2021-quantum-matter-seminar/
LOCATION:MA
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210412T100000
DTEND;TZID=America/New_York:20210412T110000
DTSTAMP:20260506T163757
CREATED:20240126T065811Z
LAST-MODIFIED:20240126T065811Z
UID:10001391-1618221600-1618225200@cmsa.fas.harvard.edu
SUMMARY:4/12/2021 Mathematical Physics Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-12-2021-mathematical-physics-seminar/
LOCATION:MA
CATEGORIES:Mathematical Physics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210408T130000
DTEND;TZID=America/New_York:20210408T143000
DTSTAMP:20260506T163757
CREATED:20240126T072647Z
LAST-MODIFIED:20240126T072647Z
UID:10001395-1617886800-1617892200@cmsa.fas.harvard.edu
SUMMARY:4/8/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-8-2021-quantum-matter-seminar/
LOCATION:MA
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210408T120000
DTEND;TZID=America/New_York:20210408T130000
DTSTAMP:20260506T163757
CREATED:20240126T072252Z
LAST-MODIFIED:20240126T072252Z
UID:10001392-1617883200-1617886800@cmsa.fas.harvard.edu
SUMMARY:4/8/2021 Interdisciplinary Science Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-8-2021-interdisciplinary-science-seminar/
LOCATION:MA
CATEGORIES:Interdisciplinary Science Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210408T090000
DTEND;TZID=America/New_York:20210408T103000
DTSTAMP:20260506T163757
CREATED:20230707T171436Z
LAST-MODIFIED:20250328T201342Z
UID:10000909-1617872400-1617877800@cmsa.fas.harvard.edu
SUMMARY:CMSA Math-Science Literature Lecture: Quantum error correcting codes and fault tolerance
DESCRIPTION:Peter Shor (MIT) \nTitle: Quantum error correcting codes and fault tolerance \nAbstract: We will go over the fundamentals of quantum error correction and fault tolerance and survey some of the recent developments in the field.\n\nTalk chair: Zhengwei Liu \nVideo
URL:https://cmsa.fas.harvard.edu/event/cmsa-math-science-literature-lecture_shor/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Lecture_Shor.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210407T150000
DTEND;TZID=America/New_York:20210407T160000
DTSTAMP:20260506T163757
CREATED:20240126T073259Z
LAST-MODIFIED:20240515T193258Z
UID:10001398-1617807600-1617811200@cmsa.fas.harvard.edu
SUMMARY:Type theory from the perspective of artificial intelligence
DESCRIPTION:Speaker: David McAllester – Toyota Technological Institute at Chicago \nTitle: Type theory from the perspective of artificial intelligence \nAbstract: This talk will discuss dependent type theory from the perspective of artificial intelligence and cognitive science. From an artificial intelligence perspective it will be argued that type theory is central to defining the “game” of mathematics — an action space and reward structure for pure mathematics. From a cognitive science perspective type theory provides a model of the grammar of the colloquial (natural) language of mathematics. Of particular interest is the notion of a signature-axiom structure class and the three fundamental notions of equality in mathematics — set-theoretic equality between structure elements\, isomorphism between structures\, and Birkoff and Rota’s notion of cryptomorphism between structure classes. This talk will present a version of type theory based on set-theoretic semantics and the 1930’s notion of structure and isomorphism given by the Bourbaki group of mathematicians. It will be argued that this “Bourbaki type theory” (BTT) is more natural and accessible to classically trained mathematicians than Martin-Löf type theory (MLTT). BTT avoids the Curry-Howard isomorphism and axiom J of MLTT. The talk will also discuss BTT as a model of MLTT. The BTT model is similar to the groupoid model in that propositional equality is interpreted as isomorphism but different in various details. The talk will also briefly mention initial thoughts in defining an action space and reward structure for a game of mathematics.
URL:https://cmsa.fas.harvard.edu/event/4-7-2021-new-technologies-in-mathematics-seminar/
LOCATION:MA
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-New-Technologies-in-Mathematics-04.07.21.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210407T140000
DTEND;TZID=America/New_York:20210407T150000
DTSTAMP:20260506T163757
CREATED:20240126T072535Z
LAST-MODIFIED:20240126T072535Z
UID:10001394-1617804000-1617807600@cmsa.fas.harvard.edu
SUMMARY:4/7/2021 Random Matrix and Probability Theory Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-7-2021-random-matrix-and-probability-theory-seminar/
LOCATION:MA
CATEGORIES:Random Matrix & Probability Theory Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210407T103000
DTEND;TZID=America/New_York:20210407T120000
DTSTAMP:20260506T163757
CREATED:20240126T072803Z
LAST-MODIFIED:20240126T072803Z
UID:10001396-1617791400-1617796800@cmsa.fas.harvard.edu
SUMMARY:4/7/2021 Quantum Matter in Mathematics and Physics
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-7-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:MA
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210406T113000
DTEND;TZID=America/New_York:20210406T123000
DTSTAMP:20260506T163757
CREATED:20240126T073134Z
LAST-MODIFIED:20240126T073134Z
UID:10001397-1617708600-1617712200@cmsa.fas.harvard.edu
SUMMARY:4/6/2021 Computer Science for Mathematicians
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-6-2021-computer-science-for-mathematicians/
LOCATION:MA
CATEGORIES:Computer Science for Mathematicians Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210406T090000
DTEND;TZID=America/New_York:20210406T103000
DTSTAMP:20260506T163757
CREATED:20230707T115709Z
LAST-MODIFIED:20250328T201336Z
UID:10000907-1617699600-1617705000@cmsa.fas.harvard.edu
SUMMARY:CMSA Math-Science Literature Lecture: Isadore Singer’s Work on Analytic Torsion
DESCRIPTION:Edward Witten (IAS) \nTitle: Isadore Singer’s Work on Analytic Torsion \nAbstract:  I will review two famous papers of Ray and Singer on analytic torsion written approximately half a century ago. Then I will sketch the influence of analytic torsion in a variety of areas of physics including anomalies\, topological field theory\, and string theory. \nThis talk is part of a subprogram of the Mathematical Science Literature Lecture series\, a Memorial Conference for the founders of index theory: Atiyah\, Bott\, Hirzebruch\, and Singer. \nTalk chair: Cumrun Vafa \nSlides | Video
URL:https://cmsa.fas.harvard.edu/event/cmsa-math-science-literature-lecture_witten-2/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series,Public Lecture,Special Lectures
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/Lecture_Witten.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210405T100000
DTEND;TZID=America/New_York:20210405T110000
DTSTAMP:20260506T163757
CREATED:20240126T080609Z
LAST-MODIFIED:20240126T080609Z
UID:10001402-1617616800-1617620400@cmsa.fas.harvard.edu
SUMMARY:4/5/2021 Math Physics Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-5-2021-math-physics-seminar/
LOCATION:MA
CATEGORIES:Mathematical Physics Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210405T100000
DTEND;TZID=America/New_York:20210405T110000
DTSTAMP:20260506T163757
CREATED:20240126T080407Z
LAST-MODIFIED:20240126T080407Z
UID:10001401-1617616800-1617620400@cmsa.fas.harvard.edu
SUMMARY:4/5/2021 Interdisciplinary Science Seminar
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-5-2021-interdisciplinary-science-seminar/
LOCATION:MA
CATEGORIES:Interdisciplinary Science Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210401T090000
DTEND;TZID=America/New_York:20210401T100000
DTSTAMP:20260506T163757
CREATED:20240126T080152Z
LAST-MODIFIED:20240126T080152Z
UID:10001400-1617267600-1617271200@cmsa.fas.harvard.edu
SUMMARY:4/1/2021 Strongly Correlated Quantum Materials
DESCRIPTION:
URL:https://cmsa.fas.harvard.edu/event/4-1-2021-strongly-correlated-quantum-materials/
LOCATION:MA
CATEGORIES:Strongly Correlated Quantum Materials and High-Temperature Superconductors
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DTSTART;TZID=America/New_York:20210331T150000
DTEND;TZID=America/New_York:20210331T160000
DTSTAMP:20260506T163757
CREATED:20240126T083143Z
LAST-MODIFIED:20240515T195507Z
UID:10001412-1617202800-1617206400@cmsa.fas.harvard.edu
SUMMARY:Doing Mathematics with Simple Types: Infinitary Combinatorics in Isabelle/HOL
DESCRIPTION:Speaker: Lawrence Paulson\, University of Cambridge Computer Laboratory  \nTitle: Doing Mathematics with Simple Types: Infinitary Combinatorics in Isabelle/HOL  \nAbstract: Are proof assistants relevant to mathematics? One approach to this question is to explore the breadth of mathematical topics that can be formalised. The partition calculus was introduced by Erdös and R. Rado in 1956 as the study of “analogues and extensions of Ramsey’s theorem”. Highly technical results were obtained by Erdös-Milner\, Specker and Larson (among many others) for the particular case of ordinal partition relations\, which is concerned with countable ordinals and order types. Much of this material was formalised last year (with the assistance of Džamonja and Koutsoukou-Argyraki). Some highlights of this work will be presented along with general observations about the formalisation of mathematics\, including ZFC\, in simple type theory. \n\n\n\n\n\n\n\n\n 
URL:https://cmsa.fas.harvard.edu/event/3-31-2021-new-tech-in-math/
LOCATION:MA
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://cmsa.fas.harvard.edu/media/CMSA-New-Technologies-in-Mathematics-03.31.21.png
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DTSTART;TZID=America/New_York:20210331T140000
DTEND;TZID=America/New_York:20210331T150000
DTSTAMP:20260506T163757
CREATED:20240212T073957Z
LAST-MODIFIED:20240212T073957Z
UID:10001877-1617199200-1617202800@cmsa.fas.harvard.edu
SUMMARY:Random Matrix & Probability Theory Seminar
DESCRIPTION:Beginning immediately\, until at least December 31\, all seminars will take place virtually\, through Zoom.\nIn the 2020-2021 AY\, the Random Matrix and Probability Theory Seminar will take place on select Wednesdays from 2:00 – 3:00pm virtually. This seminar is organized by Christian Brennecke (brennecke@math.harvard.edu ). \nTo learn how to attend this seminar\, please fill out this form. \nThe schedule below will be updated as the details are confirmed. \nSpring 2021:\n\n\n\n\nDate\nSpeaker\nTitle/Abstract\n\n\n\n\n3/31/2021\nPhilippe Sosoe\, Cornell University\nTitle:  Fluctuation bounds for O’Connell-Yor type systems \nAbstract: The O’Connell-Yor polymer is a fundamental model of a polymer in a random environment. It corresponds to the positive temperature version of Brownian Last Passage percolation. Although much is known about this model thanks to remarkable algebraic structure uncovered by O’Connell\, Yor and others\, basic estimates for the behavior of the tails of the centered partition function for finite N that are available for zero temperature models are missing. I will present an iterative estimate to obtain strong concentration and localization bounds  for the O’Connell-Yor polymer on an almost optimal scale N^{1/3+\epsilon}. \nIn the second part of the talk\, I will introduce a system of interacting diffusions describing the successive increments of partition functions of different sizes. For this system\, the N^{2/3} variance upper bound known for the OY polymer can be proved for a general class of interactions which are not expected to correspond to integrable models. \nJoint work with Christian Noack and Benjamin Landon.\n\n\n4/7/2021\nYue M. Lu\, Harvard\nTitle: Householder Dice: A Matrix-Free Algorithm for Simulating Dynamics on Random Matrices\n\nAbstract: In many problems in statistical learning\, random matrix theory\, and statistical physics\, one needs to simulate dynamics on random matrix ensembles. A classical example is to use iterative methods to compute the extremal eigenvalues/eigenvectors of a (spiked) random matrix. Other examples include approximate message passing on dense random graphs\, and gradient descent algorithms for solving learning and estimation problems with random initialization. We will show that all such dynamics can be simulated by an efficient matrix-free scheme\, if the random matrix is drawn from an ensemble with translation-invariant properties. Examples of such ensembles include the i.i.d. Gaussian (i.e. the rectangular Ginibre) ensemble\, the Haar-distributed random orthogonal ensemble\, the Gaussian orthogonal ensemble\, and their complex-valued counterparts.A “direct” approach to the simulation\, where one first generates a dense n × n matrix from the ensemble\, requires at least O(n^2) resource in space and time. The new algorithm\, named Householder Dice (HD)\, overcomes this O(n^2) bottleneck by using the principle of deferred decisions: rather than fixing the entire random matrix in advance\, it lets the randomness unfold with the dynamics. At the heart of this matrix-free algorithm is an adaptive and recursive construction of (random) Householder reflectors. These orthogonal transformations exploit the group symmetry of the matrix ensembles\, while simultaneously maintaining the statistical correlations induced by the dynamics. The memory and computation costs of the HD algorithm are O(nT) and O(n T^2)\, respectively\, with T being the number of iterations. When T ≪ n\, which is nearly always the case in practice\, the new algorithm leads to significant reductions in runtime and memory footprint.Finally\, the HD algorithm is not just a computational trick. I will show how its construction can serve as a simple proof technique for several problems in high-dimensional estimation\n\n\n4/14/2021\nCanceled\n\n\n\n4/16/2021\nFriday\nPatrick Lopatto (IAS)\nTitle: Fluctuations in local quantum unique ergodicity for generalized Wigner matrices \nAbstract: In a disordered quantum system\, delocalization can be understood in many ways. One of these is quantum unique ergodicity\, which was proven in the random matrix context by Bourgade and Yau. It states that for a given eigenvector and set of coordinates J\, the mass placed on J by the eigenvector tends to N^{-1}|J|\, the mass placed on those coordinates by the uniform distribution. Notably\, this convergence holds for any size of J\, showing that the eigenvectors distribute evenly on all scales. \nI will present a result which establishes that the fluctuations of these averages are Gaussian on scales where |J| is asymptotically less than N\, for generalized Wigner matrices with smooth entries. The proof uses new eigenvector observables\, which are analyzed dynamically using the eigenvector moment flow and the maximum principle. \nThis is joint work with Lucas Benigni.\n\n\n4/21/2021\nJean-Christophe Mourrat\, Courant Institute\, NYU\nTitle: Mean-field spin glasses: beyond Parisi’s formula?\n\nAbstract: Spin glasses are models of statistical mechanics encoding disordered interactions between many simple units. One of the fundamental quantities of interest is the free energy of the model\, in the limit when the number of units tends to infinity. For a restricted class of models\, this limit was predicted by Parisi\, and later rigorously proved by Guerra and Talagrand. I will first show how to rephrase this result using an infinite-dimensional Hamilton-Jacobi equation. I will then present partial results suggesting that this new point of view may allow to understand limit free energies for a larger class of models\, focusing in particular on the case in which the units are organized over two layers\, and only interact across layers.\n\n\n\n\n\nFall 2020:\n\n\n\n\nDate\nSpeaker\nTitle/Abstract\n\n\n\n\n9/9/2020\nYukun He (Zurich)\nTitle: Single eigenvalue fluctuations of sparse Erdős–Rényi graphs \nAbstract: I discuss the fluctuations of individual eigenvalues of the adjacency matrix of the Erdös-Rényi graph $G(N\,p)$. I show that if $N^{-1}\ll p \ll N^{-2/3}\, then all nontrivial eigenvalues away from 0 have asymptotically Gaussian fluctuations. These fluctuations are governed by a single random variable\, which has the interpretation of the total degree of the graph. The main technical tool of the proof is a rigidity bound of accuracy $N^{-1-\varepsilon}p^{-1/2}$ for the extreme eigenvalues\, which avoids the $(Np)^{-1}$-expansions from previous works. Joint work with Antti Knowles.\n\n\n10/14/2020\nDavid Belius (University of Basel)\nTitle: The TAP approach to mean field spin glasses \nAbstract: The Thouless-Anderson-Palmer (TAP) approach to the Sherrington-Kirkpatrick mean field spin glass model was proposed in one of the earliest papers on this model. Since then it has complemented subsequently elaborated methods  in theoretical physics and mathematics\, such as the replica method\, which are largely orthogonal to the TAP approach. The TAP approach has the advantage of being interpretable as a variational principle optimizing an energy/entropy trade-off\, as commonly encountered in statistical physics and large deviations theory\, and potentially allowing for a more direct characterization of the Gibbs measure and its “pure states”. In this talk I will recall the TAP approach\, and present preliminary steps towards a solution of mean field spin glass models entirely within a TAP framework.\n\n\n10/28/2020\nGiuseppe Genovese (University of Basel)\nTitle: Non-convex variational principles for the RS free energy of restricted Boltzmann machines \nAbstract: From the viewpoint of spin glass theory\, restricted Boltzmann machines represent a veritable challenge\, as to the lack of convexity prevents us to use Guerra’s bounds. Therefore even the replica symmetric approximation for the free energy presents some challenges. I will present old and new results around the topic along with some open problems.\n\n\n11/4/2020\nBenjamin Landon (MIT)\nTitle:  Fluctuations of the spherical Sherrington-Kirkpatrick model \nAbstract:  The SSK model was introduced by Kosterlitz\, Thouless and Jones as a simplification of the usual SK model with Ising spins. Fluctuations of its observables may be related to quantities from random matrix theory using integral representations.  In this informal talk we discuss some results on fluctuations of this model at critical temperature and with a magnetic field\n\n\n11/11/2020\n3:00 – 4:00pm\nLucas Benigni (University of Chicago)\nTitle:  Optimal delocalization for generalized Wigner matrices \nAbstract: We consider eigenvector statistics of large symmetric random matrices. When the matrix entries are sampled from independent Gaussian random variables\, eigenvectors are uniformly distributed on the sphere and numerous properties can be computed exactly. In particular\, we can bound their extremal coordinates with high probability. There has been an extensive amount of work on generalizing such a result\, known as delocalization\, to more general entry distributions. After giving a brief overview of the previous results going in this direction\, we present an optimal delocalization result for matrices with sub-exponential entries for all eigenvectors. The proof is based on the dynamical method introduced by Erdos-Yau\, an analysis of high moments of eigenvectors as well as new level repulsion estimates which will be presented during the talk. This is based on a joint work with P. Lopatto.\n\n\n11/18/2020\nSimone Warzel (Technical University of Munich)\nTitle:  Hierarchical quantum spin glasses\n\nAbstract: Hierarchical spin glasses such as the generalised random energy model are known to faithfully model typical energy landscapes in the classical theory of mean-field spin glasses. Their built-in hierarchical structure is known to emerge spontaneously in the spin-glass phase of\, e.g.\, the Sherrington-Kirkpatrick model. In this talk\, I will review recent results on the effects of a transversal magnetic field on such hierarchical quantum spin glasses.\nIn particular\, I will present a formula of Parisi-type for their free energy which allows to make predictions about the phase diagram.\n\n\n12/2/2020\nSabine Jansen (LMU Munich)\nTitle: Thermodynamics of a hierarchical mixture of cubes\n\nAbstract: The talk discusses a toy model for phase transitions in mixtures of incompressible droplets. The model consists of non-overlapping hypercubes of side-lengths 2^j\, j\in \N_0. Cubes belong to an admissible set such that if two cubes overlap\, then one cube is contained in the other\, a picture reminiscent of Mandelbrot’s fractal percolation model. I will present exact formulas for the entropy and pressure\, discuss phase transitions from a fluid phase with small cubes towards a condensed phase with a macroscopic cube\, and briefly sketch some broader questions on renormalization and cluster expansions that motivate the model. Based on arXiv:1909.09546 (J. Stat. Phys. 179 (2020)\, 309-340).\n\n\n\n\nFor information on previous seminars\, click here \nThe schedule will be updated as details are confirmed.
URL:https://cmsa.fas.harvard.edu/event/random-matrix-probability-theory-seminar/
LOCATION:MA
CATEGORIES:Random Matrix & Probability Theory Seminar
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