High Energy Physics Seminar TOMORROW

[Andrei Khmelnitsky]

*************************************
HIGH ENERGY PHYSICS SEMINAR
*************************************


TUESDAY, 6 DECEMBER 2016, 16:30 p.m.
Luigi Stasi SEMINAR ROOM - ICTP Leonardo Bldg.


Ashish SHUKLA
(TIFR, Mumbai, India)


"Symmetry Constraints in Inflation"

Cosmological inflation gives rise to the homogeneous and isotropic universe
we observe today, as well as generates quantum perturbations which lead to
CMB anisotropies and the formation of large scale structure. The geometry
of the universe during inflation is approximately de Sitter space. We will
discuss the interesting constraints imposed on the correlation functions of
inflationary perturbations by the underlying spatial reparametrization
invariance of the theory in single field models of inflation. The
constraints are in the form of *Ward identities* for scaling and special
conformal transformations, which are isometries of de Sitter space. We will
discuss the implications of these constraints for the scalar three point
function. We will also study the constraints when the possibility for the
universe to have started from a non Bunch-Davies vacuum state, in
particular the de Sitter invariant alpha-vacua states, is considered.