Abstract The Laser Interferometer Space Antenna (LISA) has two scientific objectives of
cosmological focus: to probe the expansion rate of the universe, and to understand …

We review the physics and phenomenology of wave dark matter: a bosonic dark matter
candidate lighter than about 30 eV. Such particles have a de Broglie wavelength exceeding …

We analyze cosmic superstring models in light of NANOGrav 15-year pulsar timing data. A
good fit is found for a string tension G μ∼ 10-12–10-11 and a string intercommutation …

Pulsar timing data used to provide upper limits on a possible stochastic gravitational wave
background (SGWB). However, the NANOGrav Collaboration has recently reported strong …

The North American Nanohertz Observatory for Gravitational Waves has recently reported
strong evidence for a stochastic common-spectrum process affecting the pulsar timing …

A bstract It is widely believed that consistent theories of quantum gravity satisfy two basic
kinematic constraints: they are free from any global symmetry, and they contain a complete …

Cosmic string networks offer one of the best prospects for detection of cosmological
gravitational waves (GWs). The combined incoherent GW emission of a large number of …

Many symmetry breaking patterns in grand unified theories (GUTs) give rise to cosmic
strings that eventually decay when pairs of GUT monopoles spontaneously nucleate along …

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 …

The past two decades have seen transformative advances in cosmology and string theory.
Observations of the cosmic microwave background have revealed strong evidence for …