Abstract: Blazars are among the most powerful objects in the Universe. These active galactic nuclei launch a relativistic jet that is viewed under a small inclination angle from Earth. They are characterized by a high time variability along the whole electromagnetic spectrum, reaching from scales of minutes to years. Is the time period between such blazar flares declining, then they can be caused by jet precession in an inspiraling supermassive binary black hole at the blazar center.
 

Studies of solar neutrinos have been tremendously important, revealing the nature of the Sun’s power source and that its neutrino flux is strongly affected by flavor mixing.  Nowadays, one gets the impression that this field is over.  However, this is not due to a lack of interesting questions; it is due to a lack of experimental progress.  I show how this can be solved, opening opportunities for discoveries in particle physics and astrophysics, simultaneously.

To be announced.

I will describe how causality implies certain non-perturbative analyticity and exponential boundedness conditions on correlators of relativistic QFTs, in a mixed (t,k) representation. I will then discuss their implications for correlators in Lorentz-breaking backgrounds, including finite-density states and cosmological spacetimes, and show how they can be used to derive a positivity condition on inflationary theories. Along the way, I will compare with the case of S-matrix positivity in flat space Lorentz-invariant theories.

Dissipation and noise arise from the incomplete modelling of unknown environments through which light and gravitational waves propagate. In this talk, I will introduce a framework that extends effective field theories to account for these effects. I will highlight how symmetries, locality, and unitarity impose constraints on dissipation and noise. Finally, I will explore the resulting phenomenology in the early and late universe, with a focus on the potential observational signatures of these effects.