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

## Magnitude homologyAdd to your list(s) Download to your calendar using vCal - Tom Leinster (University of Edinburgh)
- Tuesday 30 May 2017, 14:15-15:15
- MR5, Centre for Mathematical Sciences.
If you have a question about this talk, please contact Tamara von Glehn. Magnitude homology is a homology theory of enriched categories, proposed by Michael Shulman late last year. For ordinary categories, it is the usual homology of a category (or equivalently, of its classifying space). But for metric spaces, regarded as enriched categories à la Lawvere, magnitude homology is something new. It gives truly metric information: for instance, the first homology of a subset X of R^n detects whether X is convex. Like all homology theories, magnitude homology has an Euler characteristic, defined as the alternating sum of the ranks of the homology groups. Often this sum diverges, so we have to use some formal trickery to evaluate it. In this way, we end up with an Euler characteristic that is often not an integer. This number is called the “magnitude” of the enriched category. In topological settings it is the ordinary Euler characteristic, and in metric settings it is closely related to volume, surface area and other classical invariants of geometry. This talk is part of the Category Theory Seminar series. ## This talk is included in these lists:- All CMS events
- All Talks (aka the CURE list)
- CMS Events
- Category Theory Seminar
- DPMMS Lists
- DPMMS Pure Maths Seminar
- DPMMS info aggregator
- DPMMS lists
- MR5, Centre for Mathematical Sciences
- School of Physical Sciences
Note that ex-directory lists are not shown. |
## Other listsMeeting the Challenge of Healthy Ageing in the 21st Century Centre for Environment Energy and Natural resource Governance (C-EENRG) Seminar Series Latin American## Other talksVibration performance of London's Millennium footbridge Merck, Sharp & Dohme Lecture Exploring the Universe with Gravitational Waves: LIGO and Beyond The history of failure: a chronicle of losers or key to success? The Multiple Demand System and its subnetworks/ Crosstalk functions as feature selection in MEG source space decoding Cambridge ESRC DTC Annual Lecture 2017: After Brexit, UKRI if you want to: a social scientist's field guide to the new research landscape |