Academics

Improved Bounds for Sampling Solutions of Random CNF Formulas

Time:Wed., 14:00-15:00, April 26, 2023

Venue:Ning Zhai W11

Organizer:吴昊,杨帆,姜建平,顾陈琳

Speaker:Kuan Yang 杨宽(上海交通大学)

Abstract

Let Φ be a random k-CNF formula on n variables and m clauses, where each clause is a disjunction of k literals chosen independently and uniformly. Our goal is, for most Φ, to (approximately) uniformly sample from its solution space.

Let α=m/n be the density. The previous best algorithm runs in time n^poly(k,α) for any α≲2^(k/300) [Galanis, Goldberg, Guo, and Yang, SIAM J. Comput.'21]. In contrast, our algorithm runs in near-linear time for any α≲2^(k/3). This work was published in SODA'23.


About the speaker

I am an assistant professor in the John Hopcroft Center for Computer Science at Shanghai Jiao Tong University.

I was awarded the Ph.D. degree in Computer Science by the University of Oxford in 2020, where I was supervised by Prof. Leslie Ann Goldberg and Prof. Andreas Galanis. I was a member of St. Hugh's College at Oxford, and also a Clarendon scholar, fully-funded by the Clarendon Scholarship from 2015 to 2019. Before coming to Oxford, I obtained my bachelor degree in Computer Science from Zhiyuan College at Shanghai Jiao Tong University in China.

I am interested in many aspects of theoretical computer science, discrete probability and combinatorics. Currently I mainly work on designing and analysing approximation algorithms for counting and sampling problems.

DATEApril 26, 2023
SHARE
Related News
    • 0

      Design of gradient flows for sampling probability distributions

      AbstractSampling a target distribution with an unknown normalization constant is a fundamental problem in computational science and engineering. Often, dynamical systems of probability densities are constructed to address this task, including MCMC and sequential Monte Carlo. Recently, gradient flows in the space of probability measures have been increasingly popular to generate this dynamical s...

    • 1

      Asymptotic behavior of solutions of an isomonodromy equation

      AbstractIn this talk, we will be concerned with the isomonodromy equation corresponding to the linear differential system with coefficients u+A/z, and introduce the asymptotic behavior and series expansion of its solutions at a certain boundary point. Our main technique is to apply the Riemann-Hilbert mapping at this boundary point