New York General Relativity Seminar
We meet 23 times per semester most semesters alternating between Columbia, Stony Brook and the CUNY Graduate Center.
Current organizers: Marcus Khuri, Dan Lee, Henri Roesch, Christina Sormani, and MuTao Wang.
Past organizers include Mike Anderson, PoNing Chen, Sergiu Klainerman, and LanHsuan Huang.
June 13, 2019 at IAS Simonyi Hall 101
Feb 7, 2019 at Columbia Math Bldg 507:
Speaker Pengyu Le 34 pm
Speaker Christos Mantoulidis 4:305:30 pm
Abstract: (Joint work with P. Miao and L.F. Tam.) We derive new inequalities between the boundary capacity of an asymptotically flat 3manifold with nonnegative scalar curvature and boundary quantities that relate to quasilocal mass; one relates to BrownYork mass and the other is new. Among other things, our work yields new variational characterizations of Riemannian Schwarzschild manifolds and new comparison results for surfaces in them. Nov 29, 2018 at CUNYGC in 3305:
Hyun Chul Jang (U Conn) 3:004:00 pm
Abstract: Recently, Huang and Lee proved the rigidity of the spacetime positive mass theorem by using a variational approach. Motivated by this work, we prove that assuming the nonnegativity of the mass of asymptotically hyperbolic Riemannian manifolds (without boundary) with scalar curvature greater than or equal to n(n1), the mass is zero if and only if the manifold is isometric to the standard hyperbolic space. By a variational approach, we first prove the existence of a static potential for AH manifolds with zero mass (in fact, AH manifolds with minimal mass), and then conclude the proof by using the certain integral identity which has been discovered first by Wang. Furthermore, by using this integral identity, we prove that for a static, asymptotically locally hyperbolic manifold with a certain boundary condition, the mass is zero if and only if the manifold is isometric to (some portion of) the reference manifold to which it is asymptotic. This is based on the joint work with LanHsuan Huang and Daniel Martin. Jeff Jauregui (Union College) 4:305:30 pm
Abstract: In general relativity, the ADM mass captures the total mass of an asymptotically flat spacelike hypersurface in a spacetime. Motivated by the conjectured nearrigidity of the positive mass theorem and by Bartnik's minimal mass extension conjecture, it is natural to study the interaction between the ADM mass and lowregularity convergence. We will discuss joint work with Dan Lee on establishing the lower semicontinuity of ADM mass for pointed C^0 convergence and SormaniWenger intrinsic flat convergence, which has shown promise for lowregularity problems in general relativity. We will make use of Huisken's isoperimetric mass concept.
Oct. 4, 2018 at Stony Brook:
Eric Woolgar (U Alberta) in Room 102 of SCGP 3:004:00 pm
Abstract: Many important theorems in Riemannian geometry depend on a lower bound for the Ricci curvature. In general relativity, \emph{energy conditions} play a similar role by providing lower bounds for components of Ricci curvature. In recent years, it has been realized that these lower bounds need only hold up to a Hessian term, or more generally a Lie derivative term. I will discuss new applications to general relativity that have arisen from this realization, including generalized singularity and splitting theorems and new results that constrain extreme black hole horizon topology. This talk is based on joint work with Greg Galloway, and with Marcus Khuri and William Wylie. Siyuan Lu (Rutgers) in Room 102 of SCGP 5:006:00 pm
Abstract: For a bounded manifold with nonnegative scalar curvature, the BrownYork quasilocal mass is nonnegative and equals to 0 iff it's a domain in Euclidean space by fundamental results of Shi and Tam. Moreover, it is shown that the inequality is equivalent to Positive mass theorem. We consider the general setting that the bounded manifold allows a horizon. We establish a localized Riemannian Penrose inequality and prove that the equality holds iff it's a domain in Schwarzschild manifold. Similar to the ShiTam case, the inequality is equivalent to Riemannian Penrose inequality. This is based on joint works with P. Miao. Previous meetings (this list may be incomplete):
April 14, 2017 at Columbia
Jeremie Szeftel
PeiKen Hung and Jordan Keller
Oct. 21, 2016 at Columbia:
Abhay Ashtekar (IGCP at Penn State)
Henri Roesch (Duke)
March 24, 2016 at CUNY
ChenYun Lin (U Toronto)
Iva Stavrov (Lewis and Clark)
May 8, 2015 at Columbia
Sergio Dain
Yakov ShlapentokhRothman
Dec 12, 2014 at Stony Brook
Lydia Bieri
Xinliang An
Oct 10, 2014 at CUNY
Robert Wald
Iva Stavrov
Philippe LeFloch
Sept 19 2014 at Columbia
Steve Liebling
Frans Pretorius
Mar 7, 2014 at Stony Brook
Spyros Alexakis
Title: A reconstruction of waves from their emitted radiation and the final states of spacetimes.
Feb 7, 2014 at Columbia
Robert Wald
Title: Dynamic and Thermodynamic Stability of Black Holes and Black Branes
Piotr Chrusciel
Title: The mass of light cone
Speakers in 2013 included:
Hugh Bray
PoNing Chen
Sergio Kleinerman
Igor Rodnianski
Mihalis Dafermos
Pengzi Miao
Stefanos Aretakis
Greg Galloway
Jim Isenberg

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