# Fotis Koutroulis: Thermal effects in Ising Cosmology

Date of publication: 6. 12. 2022

Joint FMF-JSI high energy physics seminar

Thursday

8

December

Time:

11:15 - 12:15

Location:

Tea room of F1 department (IJS) and Zoom

**Fotis Koutroulis: Thermal effects in Ising Cosmology**

We consider a real scalar field in de Sitter background and compute its thermal propagators. Using arguments from holography we propose, in a dS/CFT context, that non-trivial thermal effects as seen by an ‘out’ observer can be encoded in the anomalous dimensions of the d = 3 Ising model. One of these anomalous dimensions, the critical exponent η, fixes completely a number of cosmological observables and is almost entirely responsible for the deviation of the cosmological spectral index nS of scalar fluctuations from unity. A connection with standard Inflation may be possible at the late time regimes where the time-dependent part of the field dominates.