Particle physics today faces the challenge of explaining the mystery of dark matter, the origin
of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent …

Cosmic inflation provides a window to the highest energy densities accessible in nature, far
beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the …

A bstract Ultra-low mass primordial black holes (PBH), which may briefly dominate the
energy density of the universe but completely evaporate before the big bang …

In the presence of self-interactions, the post-inflationary evolution of the inflaton field is
driven into the non-linear regime by the resonant growth of its fluctuations. The once …

We study the landscape of lower-dimensional vacua of the standard model (SM) coupled to
gravity in the presence of the so-called “dark dimension” of size R⊥ in the micron range …

The existence of a cosmic neutrino background has been inferred indirectly from
cosmological surveys through its effect on the linear-theory evolution of primordial density …

With planned space-based and 3rd generation ground-based gravitational wave detectors
(LISA, Einstein Telescope, Cosmic Explorer), and proposed DeciHz detectors (DECIGO, Big …

The S 8/σ 8 tension in the large-scale structure can be explained by decaying dark matter
with an almost degenerate spectrum and small enough decay width. Here we propose the …

We study the possibility of testing a dark matter (DM) scenario embedded in a global lepton
number symmetry U (1) L via gravitational waves (GWs) and cosmic microwave background …

We summarize progress made in theoretical astrophysics and cosmology over the past
decade and areas of interest for the coming decade. This Report is prepared as the TF09" …