The next cosmology seminar takes place on **Friday 24th** of November,
seminar **room E349** at **2pm**. Our guest speaker will be **Bryce
Cyr** from the **Jodrell Bank Centre for Astrophysics** at the University
of Manchester (Manchester, United Kingdom).

At 2pm, room E349, **Bryce Cyr** (University of Manchester), will be talking about

### Synergies between gravitational waves and CMB spectral distortions

*In this talk, I will discuss various ways in which distortions to the
frequency spectrum of the cosmic microwave background can be used to
place constraints on stochastic backgrounds of gravitational
waves. After a brief overview of spectral distortion theory, I will
show how enhancements to the small-scale primordial power spectrum of
curvature perturbations can induce sizeable distortions. Even in the
absence of enhancements, a nearly-scale invariant spectrum presents a
target well within reach of next generation
experiments. Additionally, I will highlight how the presence of
primordial tensor modes will also lead to an inevitable (although
small) distortion signature. I will then apply this formalism to a
model of scalar induced gravitational waves (SIGWs), showcasing how
constraints on the primordial scalar power spectrum can be mapped to
the gravitational wave parameter space for these models. Time
permitting, I will also show our updated formalism can be used to
improve constraints on the parameter space of primordial black
holes.*