清北师概率Webinar
Organizers: Hao Wu, Xinyi Li and Hui He.
Past webinars, Lectures and Videos
(2020-2021， 2021-2022)
Fall
2022:
Date: 2022/ Sep. /15
Time: 10:00-11:00 am (Beijing time)
Speaker: 丁秀才 (UC Davis)
Title: A
Riemann-Hilbert approach to the perturbation theory for orthogonal polynomials
with applications
Abstract：We establish a new perturbation theory for
orthogonal polynomials using a Riemann-Hilbert approach and consider
applications in randomized numerical linear algebra and algorithmic statistics.
This new approach shows that the orthogonal polynomials with respect to two
measures can be effectively compared using the difference of their Stieltjes transforms on a suitably chosen contour. The
results are applied to analyze several numerical algorithms, including the Lanczos tridiagonalization
procedure, the Cholesky factorization and the
conjugate gradient algorithm with random inputs. This talk is based on joint
works with Thomas Trogdon.
Date: 2022/ Sep. /22
Time: 10:00-11:00 am (Beijing time)
Speaker: 李晓丹 (上海财经大学)
Title: Inverting
Ray-Knight identities on trees
Date: 2022/ Sep. /29
Time: 3:00-4:00 pm (Beijing time)
Speaker: 杨尚杰 (Bar-Ilan University)
Title: Mixing time
for the asymmetric simple exclusion process in a random environment
Date: 2022/ Oct. /13
Time: 3:00-4:00 pm (Beijing time)
Speaker: 王龙敏 (Nankai University)
Title: Branching
random walks on hyperbolic groups
Abstract:
Symmetric branching random walks on a non-amenable
group $\Gamma$ exhibits a weak survival phase:
there is some critical value $\lambda_c >
1$ such that for mean offspring $\lambda \in (1, \, \lambda_c]$, the population survives
forever, but eventually vacates every finite subset of the graph. In this phase, particle trails must converge
to certain boundary $\partial \Gamma$ of the graph and the random subset
$\Lambda$ of the boundary consisting all the accumulation points is called the
limit set of the branching random walk.
In this talk, we prove in the case that $\Gamma$ is a non-elementary
hyperbolic group with $\partial \Gamma$ its hyperbolic boundary, the Hausdorff dimension $h(\lambda)$
of $\Lambda$ is at most one half of the dimension of the whole boundary, and
has critical exponent $\frac{1}{2}$ at the critical
point $\lambda_c$.
Video Slides
Date: 2022/ Oct. /20
Time: 3:00-4:00 pm (Beijing time)
Speaker: 杜航 (Peking University)
Title: TBA
Abstract Video Slides
Date: 2022/ Oct. /27
Time: 3:00-4:00 pm (Beijing time)
Speaker: Wai-Kit Lam (Taiwan University)
Title: TBA
Abstract Video Slides
Date: 2022/ Nov. /03
Time: 10:00-11:00 am (Beijing time)
Speaker: 曹仕平 (Cornell University)
Title: TBA
Abstract Video Slides
Date: 2022/ Nov. /10
Time: 10:00-11:00 am (Beijing time)
Speaker: Louis Fan (Indiana University)
Title: TBA
Abstract Video Slides
Date: 2022/ Nov. /17
Time: 10:00-11:00 am (Beijing time)
Speaker: 杨帆 (北京大学)
Title: TBA
Abstract Video Slides
Date: 2022/ Nov. /24
Time: 3:00-4:00 pm (Beijing time)
Speaker: 牟宸辰 (City University of Hong Kong)
Title: TBA
Abstract Video Slides
Date: 2022/ Dec. /01
Time: 3:00-4:00 pm (Beijing time)
Speaker: 刘明昶 (Tsinghua University)
Title: TBA
Abstract Video Slides
Date: 2022/ Dec. /08
Time: 10:00-11:00 am (Beijing time)
Speaker: Wei-Kuo Chen (University of Minnesota)
Title: TBA
Abstract Video Slides
Date: 2022/ Dec. /15
Time: 3:00-4:00 pm (Beijing time)
Speaker: 肖惠 (Universität Hildesheim)
Title: TBA
Abstract Video Slides
Date: 2022/ Dec. /22
Time: 3:00-4:00 pm (Beijing time)
Speaker: 洪杰梁 (Israel Institute of Technology)
Title: TBA
Abstract Video Slides