# Challenging the foundations of generic gravity theories

**Advisor:** Ippocratis Saltas (CEICO, IP CAS)

**Funding:** Fully funded. A generous budget for travelling will be available.

**Website:** https://ceico.cz/team/researchers/ippocratis-saltas

**Contact:** saltas@fzu.cz

Various theoretical and experimental hints suggest that General Relativity (GR) is not the ultimate theory of gravity. In particular, the need to explain the problem of dark energy, or the initial conditions in the very early Universe has given rise to a multitude of theoretical extensions of General Relativity. Typically, such extensions of GR rely on the introduction of new dynamical degrees of freedom and non-trivial interactions of gravitational origin, beyond the usual graviton. In this context, along with phenomenological probes, the quest for understanding the foundations of generic gravity theories is ongoing and important.

This project aims to investigate the consistency and predictions of general theories of gravity from a fundamental perspective. Through classical and quantum field theoretical tools, the project will question aspects such as classical or quantum stability, the dynamics of the theory at extreme environments such neutron stars or black holes, or the extension of the theory in the ultraviolet, to name a few (see e.g [1,2]). The project is predominantly theoretical, however, it may also follow phenomenologically inclined directions.

A strong background in classical and quantum field theory is necessary for this project. Good knowledge of General Relativity is also desirable.

References:

[1] I. D. Saltas, V. Vitagliano, JCAP 05
(2017) 020 - arXiv:1612.08953

[2] I. D.
Saltas, JCAP 02 (2016) 048 - arXiv:1512.06134