From khavkine at math.cas.cz  Fri May  1 14:39:22 2026
From: khavkine at math.cas.cz (Igor Khavkine)
Date: Fri, 1 May 2026 14:39:22 +0200
Subject: [PHK_seminar] [Cohomology]Wednesday 29 Apr, Roee Leder
In-Reply-To: <baf46470093b0d256a12386aca6b01a4@math.cas.cz>
References: <baf46470093b0d256a12386aca6b01a4@math.cas.cz>
Message-ID: <1e1c396f-eec0-41a8-82ab-ae2506788c40@math.cas.cz>

Dear All,

The video recording of the talk by Roee Leder from this week is now 
available on YouTube at

   https://youtu.be/eqwoB6fYQ5w

The slides and the paper that the talk was based on are available from

   https://users.math.cas.cz/~hvle/PHK/leder-ricci-cohomology2026.pdf
   https://arxiv.org/abs/2510.12797

The links have also been recorded at the ResearchSeminars announcement

   https://researchseminars.org/talk/PHK-cohomology-seminar/157/

Best,

Igor

On 4/27/26 1:00 PM, sender of seminar announcement via phk_seminar wrote:
> Wednesday, 29 April 2026 - 13:30 to 14:30
> Place: Institute of Mathematics of ASCR, ?itn? 25, Praha 1, ZOOM meeting
> 
> Speaker: Roee Leder, Hebrew University of Jerusalem
> Title: Cohomology for linearized Ricci curvature
> 
> Abstract
> 
> I will present full solvability and uniqueness conditions for the 
> linearized Ricci curvature equations on compact Riemannian manifolds 
> with boundary. These equations have long resisted analysis without 
> restrictive curvature assumptions; the results I shall present are the 
> first obtained without such restrictions in the interior. The approach 
> relies on a generalized Hodge theory, based on microlocal methods, to 
> reduce the problem to the study of two newly identified cohomologies. By 
> means of Bochner technique, I also prove vanishing theorems for these 
> cohomologies: notably, by incorporating connections on Riemannian 
> metrics, the first cohomology vanishes if the boundary is convex, and 
> the second cohomology vanishes if adapted to traceless-transverse (TT) 
> tensors, and the boundary is round. I shall also discuss how this 
> cohomological formulation captures the natural gauge group of geometric 
> inverse problems and relates to the injectivity of the Lichnerowicz 
> Laplacians on TT tensors.
> 
> ------------------------------------------------------------------------------------------------------------------------------------
> 
> 
> We shall open ZOOM meeting at 13.15 for virtual coffee and close ZOOM at 
> 15.30
> 
> 
> Join Zoom Meeting
> 
> 
> https://cesnet.zoom.us/j/99598413922? 
> pwd=YXNFbk50aVhleXhWSGtISFViLytRUT09 <https://cesnet.zoom.us/ 
> j/99598413922?pwd=YXNFbk50aVhleXhWSGtISFViLytRUT09>
> 
> 
> Meeting ID:99598413922
> 
> Passcode:Galois
> 
> -------------------------------------------------------------------------------------------------------------------
> 
> On Wednesday May 6, Svatopluk Kryls shall give a lecture *Cohomology of 
> symplectic spinor twisted de Rham sequence and its subcomplexes* 
> <https://www.math.cas.cz/index.php/events/event/4134>
> 
> 
> 
> For more information see the seminar web page at
> https://www.math.cas.cz/index.php/events/seminar/16
> 
> Cohomology in algebra, geometry, physics and statistics mailing list
> phk_seminar at math.cas.cz
> https://list.math.cas.cz/listinfo/phk_seminar at math.cas.cz
> 
> 
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