The first direct measurement of gravitational waves by the LIGO and Virgo collaborations
has opened up new avenues to explore our Universe. This white paper outlines the …

It is commonly assumed that the energy density of the Universe was dominated by radiation
between reheating after inflation and the onset of matter domination 54,000 years later …

Ultracompact dark matter (DM) minihalos at masses at and below 10-12 M⊙ arise in axion
DM models where the Peccei-Quinn (PQ) symmetry is broken after inflation. The minihalos …

Compact objects occupy a pivotal role in the exploration of Nature. The interest spans from
the role of compact objects in astrophysics to their detection through various methods …

It has been a half-decade since the first direct detection of gravitational waves, which
signifies the coming of the era of the gravitational-wave astronomy and gravitational-wave …

Homogeneous oscillations of the inflaton after inflation can be unstable to small spatial
perturbations even without coupling to other fields. We show that for inflaton potentials∝| ϕ …

Oscillons are massive, long-lived, localized excitations of a scalar field. We show that in a
class of well-motivated single-field models, inflation is followed by self resonance, leading to …

The classical equations of motion for an axion with potential V (ϕ)= ma 2 fa 2 [1− cos (ϕ/fa)]
possess quasi-stable, localized, oscillating solutions, which we refer to as``axion stars''. We …

We show that fragmentation of the inflaton into long-lived spatially localized oscillon
configurations can lead to copious production of black holes. In simple inflation models …

We study the scalar and tensor perturbations generated by the fragmentation of the inflaton
condensate into oscillons or transients after inflation, using nonlinear classical lattice …