[PHK_seminar] [Cohomology]Wednesday 3 Dec, Yukihiro Okamoto

[Igor Khavkine]

Dear All,

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

   https://youtu.be/CfCKpcpzWKk

The slides are available from

   https://users.math.cas.cz/~hvle/PHK/Okamoto_Legendrian-2025.pdf

Both links have also been recorded at the ResearchSeminars announcement

   https://researchseminars.org/talk/PHK-cohomology-seminar/143/

Best,

Igor

On 12/1/25 1:00 PM, sender of seminar announcement via phk_seminar wrote:
> Wednesday, 3 December 2025 - 13:30 to 14:30
> Place: Institute of Mathematics of ASCR, Žitná 25, Praha 1, ZOOM meeting
> 
> Speaker: Yukihiro Okamoto, Tokyo Metropolitan University
> Title: Legendrian non-isotopic unit conormal bundles in high dimensions
> 
> Abstract
> 
> For any compact submanifold of R^n, its unit conormal bundle is a 
> compact Legendrian submanifold of the unit cotangent bundle of R^n.
> 
> In this talk, I will give examples of pairs of compact connected 
> submanifolds of R^n of codimension greater than 3 such that their unit 
> conormal
> 
> bundles are not Legendrian isotopic, although these two Legendrian 
> submanifolds cannot be distinguished by classical invariants.
> 
> The main tools to distinguish them are the strip Legendrian contact 
> homology and a coproduct on it. I will explain that, in a special case
> 
> including the main examples, the coproduct can be computed by using the 
> idea of string topology.
> 
> 
> ----------------------------------------------------------
> 
> 
> We shall open ZOOM meeting at 13.15 for virtual coffee and close ZOOM at 
> 15.00
> 
> 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 December 10, Professor Teimuraz Pirashvili shall give a 
> talk ``The category of finite sets and cohomology theories of commutative
> 
> algebras".
> 
> 
> 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@math.cas.cz
> 
> 
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