24–28 Aug 2026
Leiden University
Europe/Zurich timezone

Multi-soft theorems for cosmological correlators: Background wave method for scalars & gravitons

Not scheduled
20m
Gorlaeus gebouw (Leiden University)

Gorlaeus gebouw

Leiden University

Einsteinweg 55, 2333 CC Leiden
Talk Inflation / Primordial Perturbations

Speaker

Dr Farman Ullah (International Centre for Theoretical Sciences (ICTS – TIFR), Bengaluru, India)

Description

Cosmological soft theorems (or consistency relations) provide a powerful probe
for the physics of inflation. These relations rely on minimal assumptions and hold very
generally. Consequently, any violation of these relations would rule out a large class of
inflationary models. For instance, a violation of the scalar soft theorem (or consistency
relation) would rule out all attractor single-field inflation models and instead point toward
either multi-field dynamics or a non-attractor phase. In this paper, we derive tree-level
multi-soft theorems, at leading order in the soft expansion, for both scalar and tensor
correlation functions. Our analysis employs the background-wave method, in which the
effect of long-wavelength modes is captured by an appropriate spatial coordinate rescaling.
In addition, we systematically incorporate soft-exchange contributions, including tensor
exchanges in scalar correlators and scalar exchanges in tensor correlators.

Other topic / keywords: Inflation, Consistency relations, Soft Theorems

Author

Dr Farman Ullah (International Centre for Theoretical Sciences (ICTS – TIFR), Bengaluru, India)

Presentation materials

There are no materials yet.