Scalar fields have played an important role in the development of the fundamental theories
of physics as well as in other branches of physics such as gravitation and cosmology. For a …

The dawn of the twenty-first century came with very positive prospects for gravity, cosmology,
and astrophysics. Technological progress made it possible for cosmology to enter to its …

Horndeski gravity is the most general scalar tensor theory, with a single scalar field, leading
to second-order field equations and after the GW170817 it has been severely constrained …

The direct detection of gravitational waves by the LIGO/Virgo Collaboration has opened a
new window with which to measure cosmological parameters such as the Hubble constant …

The detection of a binary neutron star (BNS) merger in 2017 through both gravitational
waves and electromagnetic emission opened a new era of multimessenger astronomy. The …

In this work we shall study Einstein Gauss-Bonnet theories and we investigate when these
can have their gravitational wave speed equal to the speed of light, which is unity in natural …

Direct observation of gravitational waves offers us numerous novel possibilities to further
explore the Universe. In practice, the efficiency of the experimental facility for a given …

The article explores the dynamics and stability of compact stars in the field of f (R) gravity by
investigating the empirical data of different significant compact star candidates. We used the …

The swampland criteria are generically in tension with single-field slow-roll inflation because
the first swampland criterion requires small tensor-to-scalar ratio while the second …

General relativity predicts the existence of only two tensorial gravitational wave
polarizations, while a generic metric theory of gravity can possess up to four additional …