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BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210921T093000
DTEND;TZID=America/New_York:20210921T093000
DTSTAMP:20240304T060511Z
CREATED:20240214T050308Z
LAST-MODIFIED:20240304T060511Z
UID:10002536-1632216600-1632216600@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Surfacehedra and the Binary Positive Geometry of Particle and “String” Amplitudes
DESCRIPTION:Speaker: Nima Arkani-Hamed\, IAS \nTitle: Surfacehedra and the Binary Positive Geometry of Particle and “String” Amplitudes
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-21-2021-combinatorics-physics-and-probability-seminar/
LOCATION:Virtual
CATEGORIES:Combinatorics Physics and Probability
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210917T185400
DTEND;TZID=America/New_York:20210917T195400
DTSTAMP:20240301T094616Z
CREATED:20240214T091836Z
LAST-MODIFIED:20240301T094616Z
UID:10002617-1631904840-1631908440@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Strong Coupling Theory of Magic-Angle Graphene: A Pedagogical Introduction
DESCRIPTION:Title: Strong Coupling Theory of Magic-Angle Graphene: A Pedagogical Introduction \nAbstract: In this talk\, I will review a recently developed strong coupling theory of magic-angle twisted bilayer graphene. An advantage of this approach is that a single formulation can capture both the insulating and superconducting states\, and with a few simplifying assumptions\, can be treated analytically. I begin by reviewing the electronic structure of magic angle graphene’s flat bands\, in a limit that exposes their peculiar band topology and geometry. I will show how similarities between the flat bands and the lowest Landau level can provide valuable insights into the effect of interactions and form the basis for an analytic treatment of the problem. At integer fillings\, this approach points to flavor ordered insulators\, which can be captured by a sigma-model in its ordered phase. Remarkably\, topological textures of the sigma model carry electric charge which enables the same theory to describe the doped phases away from integer filling. I will show how this approach can lead to superconductivity on disordering the sigma model\, and estimate the Tc for the superconductor. I will highlight the important role played by an effective super-exchange coupling both in pairing and in setting the effective mass of Cooper pairs. At the end\, I will show how this theory provides criteria to predict which multilayer graphene stacks are expected to superconduct including the recently discovered alternating twist trilayer platform.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-17-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210916T184700
DTEND;TZID=America/New_York:20210916T194700
DTSTAMP:20240301T094752Z
CREATED:20240214T092053Z
LAST-MODIFIED:20240301T094752Z
UID:10002619-1631818020-1631821620@live-hu-cmsa-222.pantheonsite.io
SUMMARY:The Hilbert Space of large N Chern-Simons matter theories
DESCRIPTION:Title: The Hilbert Space of large N Chern-Simons matter theories \nAbstract: We demonstrate that all known formulae for the thermal partition function for large N Chern Simons matter theory admit a simple Hilbert Space interpretation. In each case this quantity equals the partition function of an associated ungauged large $N$ matter theory with a particular local Lagrangian with one additional element: the Fock Space of this associated theory is projected down to the subspace of its WZW singlets. This projection\, in particular\,  implies the previously encountered `Bosonic Exclusion Principle’\, namely that no single particle state can be occupied by more than $k_B$ particles ($k_B$ is the Chern Simons level). Unlike its Gauss Law counterpart\, the WZW constraint does not trivialize in the large volume limit. However thermodynamics does simplify in this limit;  the final partition function reduces to a product of partition functions associated with each single particle state. These individual single particle state partition functions are a one parameter generalizations of their free boson and free fermion counterparts\, and reduce to the later at extreme values of the ‘t Hooft coupling. At generic values of the rank and the level the occupation statistics of each energy level is given by a $q$ deformation of the usual free formulae of Bose and Fermi statistics.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-16-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210915T184600
DTEND;TZID=America/New_York:20210915T194600
DTSTAMP:20240301T094948Z
CREATED:20240214T092313Z
LAST-MODIFIED:20240301T094948Z
UID:10002623-1631731560-1631735160@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Three-particle mechanism for pairing and superconductivity
DESCRIPTION:Title: Three-particle mechanism for pairing and superconductivity \nAbstract: I will present a new mechanism and an exact theory of electron pairing due to repulsive interaction in doped insulators. When the kinetic energy is small\, the dynamics of adjacent electrons on the lattice is strongly correlated. By developing a controlled kinetic energy expansion\, I will show that two doped charges can attract and form a bound state\, despite and because of the underlying repulsion. This attraction by repulsion is enabled by the virtual excitation of a third electron in the filled band. This three-particle pairing mechanism leads to a variety of novel phenomena at finite doping\, including spin-triplet superconductivity\, pair density wave\, BCS-BEC crossover and Feshbach resonance involving “trimers”. Possible realizations in moire materials\, ZrNCl and WTe2 will be discussed. \n[1] V. Crepel and L. Fu\, Science Advances 7\, eabh2233 (2021)\n[2] V. Crepel and L. Fu\, arXiv:2103.12060\n[3] K. Slagle and L. Fu\,  Phys. Rev. B 102\, 235423 (2020)
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-15-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210915T093000
DTEND;TZID=America/New_York:20210915T103000
DTSTAMP:20240501T205627Z
CREATED:20240214T044745Z
LAST-MODIFIED:20240501T205627Z
UID:10002533-1631698200-1631701800@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Hyperbolic Geometry and Quantum Invariants
DESCRIPTION:Speaker: Tian Yang (Texas A&M University) \nTitle: Hyperbolic Geometry and Quantum Invariants \nAbstract: There are two very different approaches to 3-dimensional topology\, the hyperbolic geometry following the work of Thurston and the quantum invariants following the work of Jones and Witten. These two approaches are related by a sequence of problems called the Volume Conjectures. In this talk\, I will explain these conjectures and present some recent joint works with Ka Ho Wong related to or benefited from this relationship.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/hyperbolic-geometry-and-quantum-invariants/
LOCATION:Virtual
CATEGORIES:Colloquium
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210910T184400
DTEND;TZID=America/New_York:20210910T194400
DTSTAMP:20240301T095315Z
CREATED:20240214T092532Z
LAST-MODIFIED:20240301T095315Z
UID:10002624-1631299440-1631303040@live-hu-cmsa-222.pantheonsite.io
SUMMARY:More Exact Results in Gauge Theories: Confinement and Chiral Symmetry Breaking
DESCRIPTION:Title: More Exact Results in Gauge Theories: Confinement and Chiral Symmetry Breaking \nAbstract: In this follow-up to Hitoshi Murayama’s talk “Some Exact Results in QCD-like and Chiral Gauge Theories”\, I present a detailed analysis of the phases of $SO(N_c)$ gauge theory.\nStarting with supersymmetric $SO(N_c)$ with $N_F$ flavors\, we extrapolate to the non-supersymmetric limit using anomaly-mediated supersymmetry breaking (AMSB). Interestingly\, the abelian Coulomb and free magnetic phases do not survive supersymmetry breaking and collapse to a confining phase. This provided one of the first demonstrations of true confinement with chiral symmetry breaking in a non-SUSY theory.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-10-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210909T183800
DTEND;TZID=America/New_York:20210909T193800
DTSTAMP:20240301T095523Z
CREATED:20240214T092815Z
LAST-MODIFIED:20240301T095523Z
UID:10002628-1631212680-1631216280@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Quantum gravity from quantum matter
DESCRIPTION:Title: Quantum gravity from quantum matter \nAbstract: We present a model of quantum gravity in which dimension\, topology and geometry of spacetime are collective dynamical variables that describe the pattern of entanglement of underlying quantum matter. As spacetimes with arbitrary dimensions can emerge\, the gauge symmetry is generalized to a group that includes diffeomorphisms in general dimensions. The gauge symmetry obeys a first-class constraint operator algebra\, and is reduced to a generalized hypersurface deformation algebra in states that exhibit classical spacetimes. In the semi-classical limit\, we find a saddle-point solution that describes a series of (3+1)-dimensional de Sitter-like spacetimes with the Lorentzian signature bridged by Euclidean spaces in between.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-9-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210908T183700
DTEND;TZID=America/New_York:20210908T193700
DTSTAMP:20240301T095658Z
CREATED:20240214T093235Z
LAST-MODIFIED:20240301T095658Z
UID:10002632-1631126220-1631129820@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Cornering the universal shape of fluctuations and entanglement
DESCRIPTION:Title: Cornering the universal shape of fluctuations and entanglement \nAbstract: Understanding the fluctuations of observables is one of the main goals in physics. We investigate such fluctuations when a subregion of the full system can be observed\, focusing on geometries with corners. We report that the dependence on the opening angle is super-universal: up to a numerical prefactor\, this function does not depend on anything\, provided the system under study is uniform\, isotropic\, and correlations do not decay too slowly. The prefactor contains important physical information: we show in particular that it gives access to the long-wavelength limit of the structure factor. We illustrate our findings with several examples: classical fluids\, fractional quantum Hall (FQH) states\, scale invariant quantum critical theories\, and metals. Finally\, we discuss connections with the entanglement entropy\, including new results for Laughlin FQH states. \nRef: arXiv:2102.06223
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-8-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210902T183400
DTEND;TZID=America/New_York:20210902T193400
DTSTAMP:20240301T095944Z
CREATED:20240214T093431Z
LAST-MODIFIED:20240301T095944Z
UID:10002634-1630607640-1630611240@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Exotic quantum matter: From lattice gauge theory to hyperbolic lattices
DESCRIPTION:Title: Exotic quantum matter: From lattice gauge theory to hyperbolic lattices \nAbstract: This talk\, in two parts\, will discuss two (unrelated) instances of exotic quantum matter. In the first part\, I will discuss quantum critical points describing possible transitions out of the Dirac spin liquid\, towards either symmetry-breaking phases or topologically ordered spin liquids. I will also comment on the role of instanton zero modes for symmetry breaking in parton gauge theories. In the second part\, I will propose an extension of Bloch band theory to hyperbolic lattices\, such as those recently realized in circuit QED experiments\, based on ideas from algebraic geometry and Riemann surface theory.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-2-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210901T183100
DTEND;TZID=America/New_York:20210901T193100
DTSTAMP:20240301T100331Z
CREATED:20240214T093606Z
LAST-MODIFIED:20240301T100331Z
UID:10002639-1630521060-1630524660@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Naturalness and muon anomalous magnetic moment
DESCRIPTION:Title: Naturalness and muon anomalous magnetic moment \nAbstract: We study a model for explaining the apparent deviation of the muon anomalous magnetic moment\, (g-2)\, from the Standard Model expectation. There are no new scalars and hence no new hierarchy puzzles beyond those associated with the Standard model Higgs; the only new particles that are relevant for (g-2) are vector-like singlet and doublet leptons. Interestingly\, this simple model provides a calculable example violating the Wilsonian notion of naturalness: despite the absence of any symmetries prohibiting its generation\, the coefficient of the naively leading dimension-six operator for (g−2) vanishes at one-loop. While effective field theorists interpret this either as a surprising UV cancellation of power divergences\, or as a delicate cancellation between matching UV and calculable IR corrections to (g−2) from parametrically separated scales\, there is a simple explanation in the full theory: the loop integrand is a total derivative of a function vanishing in both the deep UV and IR. The leading contribution to (g−2) arises from dimension-eight operators\, and thus the required masses of new fermions are lower than naively expected\, with a sizable portion of parameter space already covered by direct searches at the LHC. All of the the viable parameter can be probed by the LHC and planned future colliders.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/9-1-2021-quantum-matter-in-mathematics-and-physics/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20210824
DTEND;VALUE=DATE:20210825
DTSTAMP:20250328T145235Z
CREATED:20230705T081718Z
LAST-MODIFIED:20250328T145235Z
UID:10000070-1629763200-1629849599@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Big Data Conference 2021
DESCRIPTION:On August 24\, 2021\, the CMSA hosted our seventh annual Conference on Big Data. The Conference features many speakers from the Harvard community as well as scholars from across the globe\, with talks focusing on computer science\, statistics\, math and physics\, and economics. \nThe 2021 Big Data Conference took place virtually on Zoom. \nOrganizers:  \n\nShing-Tung Yau\, William Caspar Graustein Professor of Mathematics\, Harvard University\nScott Duke Kominers\, MBA Class of 1960 Associate Professor\, Harvard Business\nHorng-Tzer Yau\, Professor of Mathematics\, Harvard University\nSergiy Verstyuk\, CMSA\, Harvard University\n\nSpeakers: \n\nAndrew Blumberg\, University of Texas at Austin\nMoran Koren\, Harvard CMSA\nHima Lakkaraju\, Harvard University\nKatrina Ligett\, The Hebrew University of Jerusalem\n\n\n\n\n\nTime (ET; Boston time)\nSpeaker\nTitle/Abstract\n\n\n9:00AM\nConference Organizers\nIntroduction and Welcome\n\n\n9:10AM – 9:55AM\nAndrew Blumberg\, University of Texas at Austin\nTitle: Robustness and stability for multidimensional persistent homology \nAbstract: A basic principle in topological data analysis is to study the shape of data by looking at multiscale homological invariants. The idea is to filter the data using a scale parameter that reflects feature size. However\, for many data sets\, it is very natural to consider multiple filtrations\, for example coming from feature scale and density. A key question that arises is how such invariants behave with respect to noise and outliers. This talk will describe a framework for understanding those questions and explore open problems in the area.\n\n\n10:00AM – 10:45AM\nKatrina Ligett\, The Hebrew University of Jerusalem\nTitle: Privacy as Stability\, for Generalization \nAbstract: Many data analysis pipelines are adaptive: the choice of which analysis to run next depends on the outcome of previous analyses. Common examples include variable selection for regression problems and hyper-parameter optimization in large-scale machine learning problems: in both cases\, common practice involves repeatedly evaluating a series of models on the same dataset. Unfortunately\, this kind of adaptive re-use of data invalidates many traditional methods of avoiding overfitting and false discovery\, and has been blamed in part for the recent flood of non-reproducible findings in the empirical sciences. An exciting line of work beginning with Dwork et al. in 2015 establishes the first formal model and first algorithmic results providing a general approach to mitigating the harms of adaptivity\, via a connection to the notion of differential privacy. In this talk\, we’ll explore the notion of differential privacy and gain some understanding of how and why it provides protection against adaptivity-driven overfitting. Many interesting questions in this space remain open. \nJoint work with: Christopher Jung (UPenn)\, Seth Neel (Harvard)\, Aaron Roth (UPenn)\, Saeed Sharifi-Malvajerdi (UPenn)\, and Moshe Shenfeld (HUJI). This talk will draw on work that appeared at NeurIPS 2019 and ITCS 2020\n\n\n10:50AM – 11:35AM\nHima Lakkaraju\, Harvard University\nTitle: Towards Reliable and Robust Model Explanations \nAbstract: As machine learning black boxes are increasingly being deployed in domains such as healthcare and criminal justice\, there is growing emphasis on building tools and techniques for explaining these black boxes in an interpretable manner. Such explanations are being leveraged by domain experts to diagnose systematic errors and underlying biases of black boxes. In this talk\, I will present some of our recent research that sheds light on the vulnerabilities of popular post hoc explanation techniques such as LIME and SHAP\, and also introduce novel methods to address some of these vulnerabilities. More specifically\, I will first demonstrate that these methods are brittle\, unstable\, and are vulnerable to a variety of adversarial attacks. Then\, I will discuss two solutions to address some of the vulnerabilities of these methods – (i) a framework based on adversarial training that is designed to make post hoc explanations more stable and robust to shifts in the underlying data; (ii) a Bayesian framework that captures the uncertainty associated with post hoc explanations and in turn allows us to generate explanations with user specified levels of confidences. I will conclude the talk by discussing results from real world datasets to both demonstrate the vulnerabilities in post hoc explanation techniques as well as the efficacy of our aforementioned solutions.\n\n\n11:40AM – 12:25PM\nMoran Koren\, Harvard CMSA\nTitle: A Gatekeeper’s Conundrum \nAbstract: Many selection processes contain a “gatekeeper”. The gatekeeper’s goal is to examine an applicant’s suitability to a proposed position before both parties endure substantial costs. Intuitively\, the introduction of a gatekeeper should reduce selection costs as unlikely applicants are sifted out. However\, we show that this is not always the case as the gatekeeper’s introduction inadvertently reduces the applicant’s expected costs and thus interferes with her self-selection. We study the conditions under which the gatekeeper’s presence improves the system’s efficiency and those conditions under which the gatekeeper’s presence induces inefficiency. Additionally\, we show that the gatekeeper can sometimes improve selection correctness by behaving strategically (i.e.\, ignore her private information with some probability).\n\n\n12:25PM\nConference Organizers\nClosing Remarks
URL:https://live-hu-cmsa-222.pantheonsite.io/event/big-data-conference-2021/
LOCATION:Virtual
CATEGORIES:Big Data Conference,Conference,Event
ATTACH;FMTTYPE=image/png:https://live-hu-cmsa-222.pantheonsite.io/media/BD_21-Poster.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210729T103000
DTEND;TZID=America/New_York:20210729T120000
DTSTAMP:20240213T085639Z
CREATED:20240213T085639Z
LAST-MODIFIED:20240213T085639Z
UID:10002273-1627554600-1627560000@live-hu-cmsa-222.pantheonsite.io
SUMMARY:The nu=5/2 enigma: Recent insights from theory and experiment
DESCRIPTION:peaker: Ady Stern & David Mross (Weizmann) \nSpeaker: Ady Stern & David Mross (Weizmann \nTitle: The nu=5/2 enigma: Recent insights from theory and experiment \nAbstract: Non-Abelian phases of matter have long inspired quantum physicists across various disciplines. The strongest experimental evidence of such a phase arises in quantum Hall systems at the filling factor 5/2 but conflicts with decades of numerical works. We will briefly introduce the 5/2 plateau and explain some of the key obstacles to identifying its topological order. We will then describe recent experimental and theoretical progress\, including a proposal for resolving the 5/2 enigma based on electrical conductance measurements.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/the-nu5-2-enigma-recent-insights-from-theory-and-experiment/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210722T090000
DTEND;TZID=America/New_York:20210722T100000
DTSTAMP:20240227T090807Z
CREATED:20240213T085509Z
LAST-MODIFIED:20240227T090807Z
UID:10002271-1626944400-1626948000@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Moduli spaces of stable pairs on algebraic surfaces
DESCRIPTION:Interdisciplinary Science Seminar \nSpeaker: Yinbang Lin (Tongji University) \nTitle: Moduli spaces of stable pairs on algebraic surfaces \nAbstract: As a variant of Grothendieck’s Quot schemes\, we introduce the moduli space of limit stable pairs. We show an example over a smooth projective algebraic surface where there is a virtual fundamental class. We are able to describe this class explicitly. We will also show an application towards moduli of sheaves.
URL:https://live-hu-cmsa-222.pantheonsite.io/event/7-22-2021-interdisciplinary-science-seminar/
LOCATION:Virtual
CATEGORIES:Interdisciplinary Science Seminar
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210715T103000
DTEND;TZID=America/New_York:20210715T123000
DTSTAMP:20240125T164707Z
CREATED:20240125T164550Z
LAST-MODIFIED:20240125T164707Z
UID:10001338-1626345000-1626352200@live-hu-cmsa-222.pantheonsite.io
SUMMARY:Hybrid Fracton Orders
DESCRIPTION:Nathanan Tantivasadakarn (Harvard) \nVideo\nTitle: Hybrid Fracton Orders \nAbstract: I will introduce a family of gapped quantum phases that exhibit the phenomenology of both conventional three-dimensional topological orders and fracton orders called “Hybrid Fracton Orders”.  First\, I will present the simplest example of such an order: the “Hybrid X-cube” model\, where excitations can be labeled identically to those of the Z2 toric code tensored with the Z2 X-cube model\, but exhibit fusion and braiding properties between the two sets of excitations. Next\, I will provide a general construction of hybrid fracton orders which inputs a finite group G and an abelian normal subgroup N and produces an exactly solvable model. Such order can host non-abelian fracton excitations when G is non-abelian. Furthermore\, the mobilities of a general excitation is dictated by the choice of N\, from which by varying\, one can view as “interpolating” between a pure 3D topological order and a pure fracton order. \nBased on 2102.09555 and 2106.03842\n\n\n\n  \n  \n 
URL:https://live-hu-cmsa-222.pantheonsite.io/event/hybrid-fracton-orders/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210707T103000
DTEND;TZID=America/New_York:20210707T120000
DTSTAMP:20240125T165153Z
CREATED:20240125T165153Z
LAST-MODIFIED:20240125T165153Z
UID:10001341-1625653800-1625659200@live-hu-cmsa-222.pantheonsite.io
SUMMARY:7/7/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/event/7-7-2021-quantum-matter-seminar/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210615T110000
DTEND;TZID=America/New_York:20210615T123000
DTSTAMP:20240216T211240Z
CREATED:20230707T173422Z
LAST-MODIFIED:20240216T211240Z
UID:10001814-1623754800-1623760200@live-hu-cmsa-222.pantheonsite.io
SUMMARY:CMSA Math-Science Literature Lecture: Nonlinear stability of Kerr black holes for small angular momentum
DESCRIPTION:Sergiu Klainerman (Princeton University) \nTitle: Nonlinear stability of Kerr black holes for small angular momentum \nAbstract: According to a well-known conjecture\,  initial data sets\,  for the Einstein vacuum equations\, sufficiently close to a Kerr solution with parameters $a\, m$\, $|a|/m <1$\, have maximal developments with complete future null infinity and with domain of outer communication (i.e complement of a future event horizon)   which approaches  (globally)  a nearby Kerr solution. I will describe the main ideas in my recent joint work with Jeremie Szeftel concerning the resolution of the conjecture for small angular momentum\, i.e. $\, $|a|/m $ sufficiently small. The work\, ArXiv:2104.11857v1\,  also depends on forthcoming work on solutions of nonlinear wave equations in realistic perturbations of Kerr\,  with Szeftel and Elena Giorgi\,  which I will also describe. \nTalk chair: Lydia Bieri  \nVideo
URL:https://live-hu-cmsa-222.pantheonsite.io/event/cmsa-math-science-literature-lecture_klainerman/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series
ATTACH;FMTTYPE=image/jpeg:https://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Klainerman-pdf.jpeg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210507T110000
DTEND;TZID=America/New_York:20210509T204500
DTSTAMP:20250328T144404Z
CREATED:20230707T173106Z
LAST-MODIFIED:20250328T144404Z
UID:10000915-1620385200-1620593100@live-hu-cmsa-222.pantheonsite.io
SUMMARY:FRG Workshop on Geometric Methods for Analyzing Discrete Shapes
DESCRIPTION:This workshop will take place May 7-9 (Friday-Sunday)\, 2021 virtually on Zoom\nThe aim of the workshop is to bring together a community of researchers in mathematics\, computer science\, and data science who develop theoretical and computational models to characterize shapes and analysis of image data. \nThis workshop is part of the NSF FRG project: Geometric and Topological Methods for Analyzing Shapes. \nThe first half of the workshop will feature talks aimed at graduate students\, newcomers\, and a broad spectrum of audiences. Christopher Bishop (Stony Brook) and Keenan Crane (Carnegie Mellon) will each give two featured talks. The remaining part will have both background and research talks. There will also be organized discussions of open problems and potential applications. \nFor the discussions\, we are soliciting open problems in mathematical theory and applications of shape analysis. You are encouraged to post problems by sending an email to geometricproblemsfrg@gmail.com. \nWe invite junior researchers to present a short talk in the workshop. The session will be held on Friday\, May 7th or Saturday\, May 8th at 4pm and are expected to be 15-20 minutes in length. It is a great opportunity to share your work and get to know others at the workshop. Depending on the number of contributed talks\, the organizers will review the submissions and let you know if you have been selected. If you are interested please send your title and abstract to tianqi@cmsa.fas.harvard.edu by the end of May 2nd. \n  \nOrganizers: \n\nDavid Glickenstein\, University of Arizona\nJoel Hass\, University of California\, Davis\nPatrice Koehl\, University of California\, Davis\nFeng Luo\, Rutgers University\, New Brunswick\nTianqi Wu\, Harvard University\nShing-Tung Yau\, Harvard University\n\nFeatured lectures: \n\nChristopher Bishop\, Stony Brook\nKeenan Crane\, Carnegie Mellon\n\nSpeakers include: \n\nMiri Ben-Chen\, Technion – Israel Institute of Technology\nAlexander Bobenko\, Technische Universität Berlin\, Germany\nUlrike Buecking\, Free University\, Germany\nNadav Dym\, Duke University\nIvan Izmestiev\, Vienna University of Technology\nYanwen Luo\, Rutgers\nStephan Tillmann\, The University of Sydney\nMax Wardetzky\, University of Goettingen\nXu Xu\, Wuhan University
URL:https://live-hu-cmsa-222.pantheonsite.io/event/frg-workshop-on-geometric-methods-for-analyzing-discrete-shapes/
LOCATION:Virtual
CATEGORIES:Event,Workshop
ATTACH;FMTTYPE=image/jpeg:https://live-hu-cmsa-222.pantheonsite.io/media/FRG-Workshop-On-Geometric-Methods-For-Analyzing-Discrete-Shapes.jpg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210427T090000
DTEND;TZID=America/New_York:20210427T103000
DTSTAMP:20250305T174246Z
CREATED:20230707T172620Z
LAST-MODIFIED:20250305T174246Z
UID:10000913-1619514000-1619519400@live-hu-cmsa-222.pantheonsite.io
SUMMARY:CMSA Math-Science Literature Lecture: Moment maps and the Yang-Mills functional
DESCRIPTION:Frances Kirwan (University of Oxford) \nTitle: Moment maps and the Yang-Mills functional \nAbstract: In the early 1980s Michael Atiyah and Raoul Bott wrote two influential papers\, ‘The Yang-Mills equations over Riemann surfaces’ and ‘The moment map and equivariant cohomology’\, bringing together ideas ranging from algebraic and symplectic geometry through algebraic topology to mathematical physics and number theory. The aim of this talk is to explain their key insights and some of the new directions towards which these papers led. \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: Peter Kronheimer \nVideo
URL:https://live-hu-cmsa-222.pantheonsite.io/event/cmsa-math-science-literature-lecture_kirwan/
LOCATION:Virtual
CATEGORIES:Event,Math Science Literature Lecture Series
ATTACH;FMTTYPE=image/png:https://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Kirwan.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210426T100000
DTEND;TZID=America/New_York:20210426T110000
DTSTAMP:20240126T064113Z
CREATED:20240126T064113Z
LAST-MODIFIED:20240126T064113Z
UID:10001381-1619431200-1619434800@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/26/2021 Math Physics Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/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:20250328T185338Z
CREATED:20230707T172354Z
LAST-MODIFIED:20250328T185338Z
UID:10000912-1619193600-1619202600@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/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://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Sahai-pdf.jpeg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210422T103000
DTEND;TZID=America/New_York:20210422T120000
DTSTAMP:20240126T064439Z
CREATED:20240126T064439Z
LAST-MODIFIED:20240126T064439Z
UID:10001383-1619087400-1619092800@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/22/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/event/4-22-2021-quantum-matter-seminar/
LOCATION:Virtual
CATEGORIES:Quantum Matter
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210421T150000
DTEND;TZID=America/New_York:20210421T160000
DTSTAMP:20240515T192602Z
CREATED:20240126T065403Z
LAST-MODIFIED:20240515T192602Z
UID:10001388-1619017200-1619020800@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/event/4-21-2021-new-tech-in-math-seminar/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://live-hu-cmsa-222.pantheonsite.io/media/CMSA-New-Technologies-in-Mathematics-04.21.21.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210421T103000
DTEND;TZID=America/New_York:20210421T120000
DTSTAMP:20240126T063939Z
CREATED:20240126T063939Z
LAST-MODIFIED:20240126T063939Z
UID:10001380-1619001000-1619006400@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/21/2021 Quantum Matter Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/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:20250328T201355Z
CREATED:20230707T172100Z
LAST-MODIFIED:20250328T201355Z
UID:10000911-1618909200-1618914600@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/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://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Freed-1.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210419T100000
DTEND;TZID=America/New_York:20210419T110000
DTSTAMP:20240126T065219Z
CREATED:20240126T065219Z
LAST-MODIFIED:20240126T065219Z
UID:10001387-1618826400-1618830000@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/19/2021 Mathematical Physics Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/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:20240126T064234Z
CREATED:20240126T064234Z
LAST-MODIFIED:20240126T064234Z
UID:10001382-1618581600-1618585200@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/16/2021 Random Matrix and Probability Theory Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/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:20250328T201348Z
CREATED:20230707T171834Z
LAST-MODIFIED:20250328T201348Z
UID:10000910-1618578000-1618583400@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/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://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Ma-1-pdf.jpeg
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210415T090000
DTEND;TZID=America/New_York:20210415T100000
DTSTAMP:20240126T065040Z
CREATED:20240126T065040Z
LAST-MODIFIED:20240126T065040Z
UID:10001386-1618477200-1618480800@live-hu-cmsa-222.pantheonsite.io
SUMMARY:4/15/2021 Interdisciplinary Science Seminar
DESCRIPTION:
URL:https://live-hu-cmsa-222.pantheonsite.io/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:20240517T194855Z
CREATED:20240126T064644Z
LAST-MODIFIED:20240517T194855Z
UID:10001384-1618412400-1618416000@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/event/4-14-2021-new-technologies-in-mathematics/
LOCATION:Virtual
CATEGORIES:New Technologies in Mathematics Seminar
ATTACH;FMTTYPE=image/png:https://live-hu-cmsa-222.pantheonsite.io/media/CMSA-New-Technologies-in-Mathematics-04.14.21.png
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=America/New_York:20210408T090000
DTEND;TZID=America/New_York:20210408T103000
DTSTAMP:20250328T201342Z
CREATED:20230707T171436Z
LAST-MODIFIED:20250328T201342Z
UID:10000909-1617872400-1617877800@live-hu-cmsa-222.pantheonsite.io
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://live-hu-cmsa-222.pantheonsite.io/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://live-hu-cmsa-222.pantheonsite.io/media/Lecture_Shor.png
END:VEVENT
END:VCALENDAR