A number of challenges to the standard Λ CDM model have been emerging during the past
few years as the accuracy of cosmological observations improves. In this review we discuss …

Abstract LiteBIRD, the Lite (Light) satellite for the study of B-mode polarization and Inflation
from cosmic background Radiation Detection, is a space mission for primordial cosmology …

Various pulsar timing array (PTA) experiments (NANOGrav, EPTA, PPTA, CPTA, including
data from InPTA) very recently reported evidence for excess red common-spectrum signals …

We review recent trends in inflationary dynamics in the context of viable modified gravity
theories. After providing a general overview of the inflationary paradigm emphasizing on …

The Hubble tension has now grown to a level of significance which can no longer be
ignored and calls for a solution which, despite a huge number of attempts, has so far eluded …

In this work we present several characteristic examples of theories of gravity and particle
physics scenarios that may yield an observable energy spectrum of stochastic primordial …

We revisit the possibility that the stochastic common-spectrum process recently detected by
the NANOGrav pulsar timing array experiment could be due to primordial gravitational …

The strong discrepancy between local and early-time (inverse distance ladder) estimates of
the Hubble constant H 0 could be pointing towards new physics beyond the concordance Λ …

New physics increasing the expansion rate just prior to recombination is among the least
unlikely solutions to the Hubble tension and would be expected to leave an important …

Black hole (BH) shadows can be used to probe new physics in the form of ultralight particles
via the phenomenon of superradiant instability. By directly affecting the BH mass and spin …