Kostas Skenderis (University of Southampton)
I will give a brief introduction to holographic renormalization and discuss recent applications.
Mr James Brister (King's College London)
In studies of Lorentz-symmetry violating QFTs, phenomenological viability is often claimed from purely classical considerations with surprisingly little attention given to the effects of quantum corrections, presumably due to their supposed "smallness" and the difficulty of their calculation. In this talk I shall give a concrete example of a model in which this assumption is shown to be false-...
I plan to discuss aspects of the asymptotic safety conjecture for gravity for actions constructed from Ricci-scalar and -tensor invariants.
Mr Ismail Bridle (University of Southampton)
Motivated by recent studies at Southampton (Morris and Dietz, JHEP 1307:064, 2013) of the f(R) approximation in Quantum Gravity have found that, in certain formulations of the truncated RG flow, the space of relevant eigenoperators is empty. We demonstrate with the well understood model of a single component scalar field in d=3 dimensions that the Single Field Approximation (SFA) used in...
Mr Nicholas Houston (King's College London)
Supergravity is a very well motivated theoretical paradigm, which, if it exists, must be broken at low energies. As such, understanding the origin of this symmetry breaking is key for making contact with known phenomenology. We detail a non-pertubative breaking mechanism for supergravity in the super-Higgs effect realised via gravitino condensation, which also provides a UV motivated,...
Dr Peter Millington (University of Manchester)
We describe the calculation of manifestly-causal transition amplitudes over finite space-time domains. Specifically, we show how such amplitudes arise naturally within the path-integral representation of the Schwinger-Keldysh closed-time path formalism of non-equilibrium thermal field theory. We conclude by highlighting a difference in the resulting loop structure compared with the usual...
Antonio Padilla (University of Nottingham)
We propose a very simple reformulation of General Relativity, which completely sequesters from gravity all of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameters in the matter sector functionals of the 4-volume element of the universe. For them to be...
I will discuss how Starobinsky inflation can be successfully embedded in a quantum gravitational context, and in particular within the scenario of Asymptotic Safety. After presenting the (non—perturbative) beta functions for Newton’s coupling G and the dimensionless R^2 coupling, I will show how an attractive, asymptotically free UV fixed point exists for the latter, while an asymptotically...
Dr Frank Saueressig (University of Mainz)
The role of time and the possibility of spacetime carrying a foliation structure are long standing questions which lately received a lot of renewed attention from the quantum gravity community. In this talk, I will review recent progress in formulating a Wetterich-type functional renormalization group equation on foliated spacetimes and outline its potential applications. In particular, I...