COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring. |

University of Cambridge > Talks.cam > Junior Algebra/Logic/Number Theory seminar > Decidability aspects of computing spectral measures

## Decidability aspects of computing spectral measuresAdd to your list(s) Download to your calendar using vCal - Lukasz Grabowski (Imperial)
- Friday 18 May 2012, 15:00-16:00
- MR13.
If you have a question about this talk, please contact Jonathan Nelson. CANCELLED Given a finitely generated group G we can fix a generating set g_1, g_2, ... g_n and consider T to be a random walk (or more general convolution operator) on the Cayley graph of G wrt the generators g_1, ..., g_n. In the talk we will investigate computational problems related to computing the spectral measure of T: in particular, is there an algorithm which answers the question “is the kernel of T non-trivial?” I will give many examples of groups where there is such an algorithm and sketch a proof why there is no such algorithm for the group H^4, where H is the lamplighter group Z_2 \wr Z. I will also explain what’s the relation between computing kernels of such convolution operators and certain invariants of CW-complexes known as l2-Betti numbers, and how the decidability aspects related to the Atiyah conjecture on l2-Betti numbers. This talk is part of the Junior Algebra/Logic/Number Theory seminar series. ## This talk is included in these lists:- All CMS events
- All Talks (aka the CURE list)
- CMS Events
- DPMMS Lists
- DPMMS Pure Maths Seminar
- DPMMS info aggregator
- DPMMS lists
- Interested Talks
- Junior Algebra/Logic/Number Theory seminar
- MR13
- School of Physical Sciences
- bld31
- ndb35's list
Note that ex-directory lists are not shown. |
## Other listsThin Film Magnetic Talks Computer Laboratory Tech Talks CRISPR Genome Editing Courses## Other talksCafe Synthetique: Synthetic Biology Industry Night Active Machine Learning: From Theory to Practice Acceleration of tropical cyclogenesis by self-aggregation feedbacks CANCELLED: The Impact of New Technology on Transport Planning The DNA oxygenase TET1 in mammalian embryonic development and epigenetic reprogramming Reconstructing deep ocean circulation pathway and strength using sediment dispersion |