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 …

This book lays out the scientific goals to be addressed by the next-generation ground-based
cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated …

A stochastic gravitational wave background is a prediction of a number of astrophysical and
cosmological phenomena including early Universe cosmology. Recently, the NANOGrav …

Stochastic gravitational wave backgrounds, predicted in many models of the early universe
and also generated by various astrophysical processes, are a powerful probe of the …

The motion of a pseudo-scalar field X during inflation naturally induces a significant
amplification of the gauge fields to which it is coupled. The amplified gauge fields can …

We discuss some implications of the recently suggested swampland conjecture|∇ V| V≳ c∼
1, together with a previous one Δ ϕ≲ 1. We list some implications for particle …

At the linear level, the gravitational wave (GW) spectrum predicted by inflation, and many of
its alternatives, can have arbitrarily small amplitude and consequently an unconstrained tilt …

There is increasing evidence from string theory that effective field theories are only reliable
over approximately sub-Planckian field excursions. The two most promising effective models …

Waveforms of gravitational waves provide information about a variety of parameters for the
binary system merging. However, standard calculations have been performed assuming a …

A bstract We discuss the possibility of entanglement islands in cosmological spacetimes with
a general perfect fluid with an equation of state w. We find that flat universes with time …