Wave optics lensing of gravitational waves in LISA-band triple systems

One of the major predictions of Einstein’s general relativity is gravitational lensing, the deflection or amplification of light by mass distributions. In my talk, I focus on gravitational wave lensing in wave optics (very long wavelength), as opposed to the standard geometric optics. I show how a supermassive black hole acts as a wave optics lens, for triple systems in in the regime of the LISA mission.

Love numbers beyond GR and non-linear scalar tidal deformation

In General Relativity (GR), including Einstein-Maxwell theory, it is remarkable that all asymptotically flat black hole (BH) solutions have vanishing Love numbers. Consequently, the Love numbers of BHs present an excellent opportunity to examine any deviations from GR. We will investigate tidal deformations concerning neutral BHs and extremal BHs in EFT of gravity. In four dimensions, the primary contribution to the tidal Love numbers of neutral BHs arises from six derivative operators, while the Love numbers of extremal BHs are subject to corrections from four derivative operators.

Positivity bounds on electromagnetic properties of media

I will talk about the constraints imposed on the electromagnetic response of general media by microcausality (commutators of local fields vanish outside the light cone) and positivity of the imaginary parts (the medium can only absorb energy from the external field). The effect of the medium is encoded in the electric and magnetic permeabilities ε(ω, k) and μ(ω, k). In the case of dielectrics, we obtain bounds on the low-energy values of the response, ε(0, 0) and μ(0, 0).

The formation and evolution of dark matter microhalos

Dark matter in the Universe can be considered as a collisionless self-gravitating fluid obeying the Vlasov-Poisson equations. In the standard picture of cosmic structure formation, the first dark matter objects to form are expected to be microhalos of roughly Earth mass and solar system size. These halos can subsequently merge to form larger dark matter halos such as that of our Galaxy. In practice, resolving dark matter dynamics relies on a N-body approach, but with the advent of exaflopic computers it now becomes possible to solve directly Vlasov dynamics in six-dimensional phase-space.

Multifield inflation (with or) without models

Since the discovery of the Higgs boson 12 years ago, terrestrial particle collider experiments have encountered a slowdown in the quest for physics beyond the Standard Model. Arguably, the upcoming decade promises a paradigm shift towards exploring high-energy physics through cosmological observations. With an abundance of data, independent datasets, and improved systematics, a new era of exploration unfolds. Theorists now strive to attain the precision level demanded by upcoming experiments.

Inflationary and Post-Inflationary Scalar Dark Matter Production

Abstract: Dark matter is one of the great mysteries of modern physics. In addition to its precise nature, its production mechanism remains unknown. In this talk I will discuss the possibility of producing scalar dark matter candidates during and after cosmic inflation. By describing the transition from an inflationary epoch to a late-time cosmology, I will describe how the dynamics of the universe can affect the production of dark matter and leave an imprint on cosmology. I will discuss the associated constraints, phenomenological consequences, and possible further developments.


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