# Planned seminars

*16 Oct 2017 14:00 Tessa Baker, *Tests of Beyond-Einstein Gravity

*23 Oct 2017 14:00 George Pappas, *Neutron stars as matter and gravity laboratories

*27 Nov 2017 14:00 Rachel Houtz, TBA*

*04 Dec 2017 14:00 Ed Copeland, TBA*

**16/10/2017 -- Tessa**

**(University of Oxford)****Baker**Time: 14:00

Place: 226

**Tests of Beyond-Einstein Gravity**Corrections to General Relativity on large distance scales are under consideration as as an explanation of cosmic acceleration. However, studying extended gravity models on an individual basis is a labour-intensive way of testing these ideas. I will explain how instead EFT-inspired parameterised methods can be used as a powerful and efficient way of testing for deviations from GR. I will outline the theoretical foundations of these techniques, and describe the current status of their observational constraints.

**23/10/2017 -- George**

**(Technical University of Lisbon)****Pappas**Time: 14:00

Place: 226

**Neutron stars as matter and gravity laboratories**

Compact objects in general and neutron stars (NSs) in particular open a window to some of the most extreme physics we can find in nature. On the one hand in the interior of NSs we can find matter in very extreme densities, exceeding nuclear densities and anything we can probe in the laboratory, while on the other hand NSs are related to the strongest gravitational fields next only to those found in black holes. Therefore studying NSs gives us access to both supranuclear densities as well as strong gravity and can be used to get information and test our theories of matter (equation of state) and gravity. The relevant properties of the structure of NSs are encoded on the spacetime around them and by studying the astrophysical processes that take place around NSs we can map that spacetime and extract these properties (i.e., the multipole moments, the equation of state, etc).

In this talk we will discuss these properties of NSs and how they are related to the properties of the spacetime around them both in GR and in one of the proposed alternative theories of gravity. We will also talk about the relation of these properties to astrophysical observables and how one could tell these theories apart.

**4/12/2017 -- Ed**

**(University of Nottingham)****Copeland**Time: 14:00

Place: 226

TBA