Prof. S. Hollands

Prof. R. Verch

Organization:

Dr. J. Zahn

**Monday, 15:15 – 16:45 (1 hour talk, followed by questions), seminar room 210 ITP
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# Schedule for the summer term 2018:

## Schedules of past terms:

- Winter 2017/18
- Summer 2017
- Winter 2016/17
- Summer 2016
- Winter 2015/16
- Summer 2015
- Winter 2014/15
- Summer 2014
- Winter 2013/2014
- Summer 2013

**Abstract:**In most classical field theories the total mass of a system is defined using the stress-energy tensor. However, in general relativity this definition ceases to work. The difficulties arise because there is no stress-energy tensor for the gravitational field and thus the total mass has to be defined otherwise. By introducing a convenient coordinate system (Bondi coordinates) far away from the system it is possible to find a satisfying description of the total mass. Building on previous results in even dimensions we show how the Bondi mass is defined in odd dimensions.

**Abstract:**We propose a conjecture: For analytic FLWR spacetimes (i.e. with analytic expansion factor a(t)), the construction method for states of low energy (SLEs) produces states that satisfy the analytic microlocal spectrum condition, if an analytic smearing function f(t) is used in their construction. Because proving the conjecture was found to be not fitting the framework of a master thesis we rather do a consistency check. We proceed to construct SLEs for the Klein-Gordon field in deSitter spacetime while specifying the mass of the Klein-Gordon field and the form of the smearing function. It is then shown that the difference of two SLEs – expressed as two-point functions – behaves analytically.

**Abstract:**tba