# Invited Speaker

### Emanuela Dimastrogiovanni

## Programme

### Atsuhisa Ota (Cambridge) Wednesday 8 14:00 - 14:30

Cosmology with the thermal-kinetic Sunyaev-Zel'dovich effect

I will talk about the cosmological information content of thermal corrections to the kinetic Sunyaev Zel'dovich (kSZ) effects. The new term has not only velocity dependence as the kSZ effect but also unique spectral dependence, which allows it to be isolated from all other CMB signals. I will show that this effect can be detected and used to reconstruct large scale velocity fields in the future.

### Maria Mylova (Swansea) Wednesday 8 14:30 - 15:00

Chiral primordial gravitational waves in extended theories of Scalar-Tensor gravity

We re-examine the problem of parity violation in single field inflation. We introduce a modified dispersion relation which, in the limit it becomes non-relativistic, supresses the cutoff scale of the effective theory leading to parametrically large chiral tensor fluctuations. This results to strongly coupled interactions, requiring us to admit changes in the physical description of the system.

### Michael Kenna-Allison (Portsmouth) Wednesday 8 15:00 - 15:30

Cosmological Perturbations in Generalised Massive Gravity

Generalised Massive Gravity is an extension of dRGT massive gravity which promotes the free parameters of the theory to functions, whilst maintaining Lorentz invariance. In this talk we study cosmological perturbations for the scalar, vector and tensor sectors and outline the no ghost and gradient instability conditions and discuss the stability of the theory.

### Guilherme Brando de Oliveira (Porstmouth) Wednesday 8 15:30 - 16:00

Exploring Early and Late Cosmology with Next Generation Surveys

Perturbations from inflation evolve into large scale structure of the late universe, and encode abundant cosmic structure formation physics. We allow freedom in the primordial power spectrum, rather than assuming a power law scale dependence, to study its impact. Combining various generations of cosmic microwave background (CMB) data and galaxy redshift survey data, we investigate the constraints on reconstruction of the primordial curvature perturbation power spectrum and the late time cosmology.

### Coffee Break

Wednesday 8 16:00 - 16:30

Coffee Break

### Francesco Pace (Manchester) Wednesday 8 16:30 - 17:00

Comparison of different approaches to the quasi-static approximation in Horndeski models

A model-independent way of parameterising effects of modified gravity models is the quasi-static approximation (QSA). I will show different approaches to the QSA and how analytical predictions for the slip and the effective gravitational constant compare to the exact numerical solution and affect observable spectra.

### Spyridon Talaganis (Lancaster) Thursday 9 10:00 - 10:30

The Distributional Stress-Energy Quadrupole

The talk is on quadrupole stress-energy-momentum tensors. I shall discuss the extension of the results about the Mathisson-Papapetrou-Dixon equations to quadrupoles. Many interesting new features have been found, which only occur for quadrupoles. This will make a valuable contribution to the understanding of the sources of gravitational waves.

### Benjamin Elder (Nottingham) Thursday 9 10:30 - 11:00

Symmetron modified gravity in Casimir force sensors

The symmetron is a quintessential example of a screened modification to gravity: it is a scalar-tensor theory that, by virtue of the scalar’s nonlinear dynamics, reduces to GR in traditional tests of gravity. However, new tests of gravity performed in the lab are capable of probing the unscreened regime, and can lead to powerful bounds on screened modified gravity. Casimir force sensors, consisting of a metal plate and sphere separated by a short distance, are one promising avenue to do so. I will present a calculation of the classical symmetron force between the plate and sphere, which will enable strong new bounds to be placed on screened modified gravity. Although the main focus of this work is for laboratory tests, the solutions we find are scale-invariant, such that this result may find application from microscopic to astrophysical scales.

### Coffee Break

Thursday 9 11:00 - 11:30

Coffee Break

### Emanuela Dimastrogiovanni (New South Wales) Thursday 9 11:30 - 12:30

Constraining primordial gravitational waves from inflation

I discuss the prospects for constraining gravitational waves from non-minimal inflationary models using: (i) the large scale structure, through the so-called "fossil" signatures; (ii) cross-correlations of tracers of the large scale structure with secondary CMB anisotropies from kinetic and polarized Sunyaev–Zel'dovich effects. I show how these different routes for testing primordial gravitational waves will help us learn more about the early universe.

## How to Get Here

We hope you're able to attend. If you have questions about the registration process, our schedule or general information, don’t hesitate to reach out. You can find all the necessary information in order to travel to Lancaster University here.

Seminar Room A007, Physics Building, Bailrigg, Lancaster LA1 4YB, UK