##### Department of Mathematics,

University of California San Diego

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### Math 295 - Mathematics Colloquium

## Mu-Tao Wang

## On the notion of quasilocal mass in general relativity

##### Abstract:

\indent One of the greatest accomplishments of the theory of general relativity in the past century is the proof of the positive mass/energy theorem for asymptotically flat spacetime. This provides the theoretical foundation for the stability of an isolated gravitating system. However, the concept of mass/energy remains a challenging problem because of the lack of a quasilocal description. Most observable physical models are finitely extended spatial regions and measurement of mass/energy on such a region is essential in many fundamental issues. In fact, among Penrose's list of major unsolved problems in classical general relativity, the first one is ``Find a suitable quasi-local definition of energy-momentum in general relativity". In this talk, I shall describe a new proposal of quasi-local mass/energy by Shing-Tung Yau of Harvard University and myself.

### May 26, 2011

### 4:00 PM

### AP&M 6402

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