"High Energy Physics - Theory"

A Survey of Gravitational Waves

We review the state of the field of gravitational wave astrophysics, framing the challenges, current observations, and future prospects within the context of the predictions of Einstein's theory of general relativity.

Dark Stars and Gravitational Waves: Topical Review

Motivated by recent observations of compact binary gravitational wave events reported by LIGO/Virgo/KAGRA, we review the basics of dark and hybrid stars and examine their probabilities as mimickers for black holes and neutron stars. This review aims …

Primordial Black Holes

We review aspect of primordial black holes, i.e., black holes which have been formed in the early Universe. Special emphasis is put on their formation, their rôle as dark matter candidates and their manifold signatures, particularly through …

Modified Gravity Approaches to the Cosmological Constant Problem

The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein's general relativity could alleviate the different problems associated with it that result from the …

Modified Gravity Approaches to the Cosmological Constant Problem

The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein's general relativity could alleviate the different problems associated with it that result from the …

Modified Theories of Gravity: Why, How and What?

General Relativity (GR) was proven via the direct detection of gravitational waves from the mergers of the binary black holes and binary neutron stars by the Advanced LIGO and Advanced Virgo detectors. These detections confirmed the prediction of GR …

Detection of Early-Universe Gravitational Wave Signatures and Fundamental Physics

Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture scientific questions about the Universe. In this white paper, we …

Lectures on Classical and Quantum Cosmology

These lecture notes introduce the reader to the hot big bang model, cosmological perturbations, gravitational waves, the cosmic microwave background, inflation, the singularity problem, the cosmological constant problem and the cosmology of quantum …

Gravitational Waves in Full, Non-Linear General Relativity

These notes provide a student-friendly introduction to the theory of gravitational waves in full, non-linear general relativity (GR). We aim for a balance between physical intuition and mathematical rigor and cover topics such as the Newman-Penrose …

Effective Field Theories of Post-Newtonian Gravity: A Comprehensive Review*

This review article presents the progress made over the last decade, since the introduction of effective field theories (EFTs) into post-Newtonian (PN) gravity. These have been put forward in the context of gravitational waves (GWs) from the compact …