# Particle Physics Seminar

## Wednesday 28^{th} October 2015 at 13:30

Poynting Small Lecture Theatre

*(tea, coffee and biscuits served at 13:15)*
# Spacetime curvature and the Higgs stability before and
after inflation

## Tommi Markkanen (Kings College, London)

**Abstract**

The best fit values for the SM parameters imply that the potential for the
Higgs boson developes a Planck-scale vacuum with negative energy, which may
result in decay of the current vacuum state. In this talk we will go through
the standard discussion of vacuum (in)stability during inflation and then
show the significance of backreaction from classical gravity. After
discussing inflationary vacuum stability, we will concentrate on the
non-perturbative effects during reheating and show that they may also induce
vacuum decay for large inflationary scales. In particular, we conclude that
inflation and reheating constrain the non-minimal coupling between the SM
Higgs and gravity to be close to 1/6. arXiv:1407.3141 and arXiv:1506.04065.