Calendar

< 2021 >
May 09 - May 15
  • 09
    May 9, 2021

    FRG Workshop on Geometric Methods for Analyzing Discrete Shapes

    11:00 AM-5:00 PM
    May 9, 2021-May 9, 2021

    The 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.

    The 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.

    Register here to attend this event

    To find out details about the event, visit the CMSA event page.

  • 10
    May 10, 2021
    No events
  • 11
    May 11, 2021

    CMSA Computer Science for Mathematicians: Computability Theory for Designing Machine Learning Algorithms

    11:30 AM-12:30 PM
    May 11, 2021

    This talk is about learning from informant, a formal model for binary classification. Illustrating examples are linear separators and other uniformly decidable sets of formal languages. Due to the learning by enumeration technique by Gold the learning process can be assumed consistent when full-information is available.
    The original model can be adjusted towards the setting of deep learning. We investigate the learnability of the set of half-spaces by these incremental learners. Moreover, they have less learning power than the full-information variant by a fundamental proof technique due to Blum and Blum. This technique can also be used to separate consistency.
    Finally, we present recent results towards a better understanding of (strong) non-U-shaped learning from binary labeled input data. To separate the syntactic variant, we employ an infinite recursion theorem by Case.

    Zoom: https://harvard.zoom.us/j/98231541450

  • 12
    May 12, 2021

    CMSA Strongly Correlated Quantum Materials and High-Temperature Superconductors Series: A unified theoretical perspective on the cuprate phase diagram

    10:30 AM-12:00 PM
    May 12, 2021

    Many features of the cuprate phase diagram are a challenge for the usual tools of solid state physics. I will show how a perspective that takes into account both the localized and delocalized aspects of conduction electrons can explain, at least qualitatively, many of these features. More specifically, I will show that the work of several groups using cluster extensions of dynamical mean-field theory sheds light on the pseudogap, on the quantum-critical point and on d-wave superconductivity. I will argue that the charge transfer gap and oxygen hole content are the best indicators of strong superconductivity and that many observations are a signature of the influence of Mott physics away from half-filling. I will also briefly comment on what information theoretic measures tell us about this problem.

    Zoom: https://harvard.zoom.us/j/977347126

  • 13
    May 13, 2021

    CMSA Interdisciplinary Science Seminar: A Tight Deterministic Algorithm for the Submodular Multiple Knapsack Problem

    9:00 AM-10:00 AM
    May 13, 2021

    Submodular function maximization has been a central topic in the theoretical computer science community over the last decade. Plenty of well-performing approximation algorithms have been designed for the maximization of (monotone or non-monotone) submodular functions over a variety of constraints. In this talk, we consider the submodular multiple knapsack problem (SMKP), which is the submodular version of the well-studied multiple knapsack problem (MKP). Roughly speaking, the problem asks to maximize a monotone submodular function over multiple bins (knapsacks). Recently, Fairstein et al. (ESA20) presented a tight (1−1/e−ϵ)-approximation randomized algorithm for SMKP. Their algorithm is based on the continuous greedy technique which inherently involves randomness. However, the deterministic algorithm of this problem has not been understood very well previously. In this paper, we present a tight (1−1/e−ϵ) deterministic algorithm for SMKP. Our algorithm is based on reducing SMKP to an exponential-size submodular maximizaion problem over a special partition matroid which enjoys a tight deterministic algorithm. We develop several techniques to mimic the algorithm, leading to a tight deterministic approximation for SMKP.

    Zoom: https://harvard.zoom.us/j/98248914765?pwd=Q01tRTVWTVBGT0lXek40VzdxdVVPQT09

    (Password: 419419)

    CMSA Quantum Matter in Mathematics and Physics: Quantum Information Theory of the Gravitational Anomaly

    10:30 AM-12:00 PM
    May 13, 2021

    I am going to argue that the non-vanishing gravitational anomaly in 2D CFT obstructs the existence of the well-defined notion of entanglement.
    As a corollary, we will also see that the non-vanishing gravitational anomaly means the non-existence of the lattice regulator generalizing the Nielsen-Ninomiya theorem.
    Time permitting, I will also comment about the variation to other anomalies and/or to 6D and 4D.
    Finally, I will conclude the talk with possible future directions, in particular the implication it might have for the island conjecture.
    The talk is based on my recent paper with Simeon Hellerman and Domenico Orlando [2101.03320].

    Zoom: https://harvard.zoom.us/j/977347126

  • 14
    May 14, 2021
    No events
  • 15
    May 15, 2021
    No events