On Banach’s isometric subspaces problem
- 👤 Speaker: Daniil Mamaev, PDMI RAS and LSGNT
- 📅 Date & Time: Wednesday 24 May 2023, 16:00 - 17:00
- 📍 Venue: MR13
Abstract
Is a normed vector space V whose n-dimensional linear subspaces are all isometric, for a fixed 2 <= n < dim V, necessarily Euclidean? This question was asked in 1932 by S. Banach and in the known cases the answer is always affirmative. In a joint work with S. Ivanov and A. Nordskova we handle `the smallest’ previously unresolved case n = 3, but the problem remains open for n 1 = dim V = 4k >= 8 and n 1= dim V = 134.
I will start by formulating the problem in a couple equivalent ways, then give an overview of previous partial results, and proceed by sketching the proof in the case n = 3. If time permits, I will also discuss the local (stronger) version of the problem and its application to Finsler geometry.
Series This talk is part of the Junior Geometry Seminar series.
Included in Lists
- All CMS events
- bld31
- CMS Events
- DPMMS info aggregator
- Hanchen DaDaDash
- Interested Talks
- Junior Geometry Seminar
- MR13
Note: Ex-directory lists are not shown.
![[Talks.cam]](/static/images/talkslogosmall.gif)


Wednesday 24 May 2023, 16:00-17:00