7 papers
Causal Horizons, Geodesic Completeness and Stability in Slow Contraction Cosmology
Mariam Khaldieh, Anna I. Rosenzweig, Paul J. Steinhardt
We show that cosmological models with a semi-infinite phase of slow contraction (ekpyrosis) possess a combination of properties that can address several fundamental problems in cos…
Holographic Constraints on the String Landscape
Alek Bedroya, Paul J. Steinhardt
We show that holography imposes strong and general constraints on scalar field potentials in the string landscape, determined by the asymptotic structure of the underlying spacetim…
Particle Production by Time-Varying Dark Energy and the End of Cosmic Expansion
Nicolas Patino, Paul J. Steinhardt
We consider various possible consequences of time-varying dark energy due to a quintessence scalar field whose energy density is partially converted to particles as the field evolv…
Holography vs. Scale Separation
Alek Bedroya, Paul J. Steinhardt
In this work, we point out a contradiction between holography and scale-separated AdS (i.e. parametrically large mass gap) in string theory, making the standard assumption that the…
Instant Folded Strings, Dark Energy and a Cyclic Bouncing Universe
Nissan Itzhaki, Uri Peleg, Paul J. Steinhardt
We present a wholly self-consistent, complete cyclic bouncing cosmology based on components drawn from string theory and constructed in a way that is under perturbative control thr…
A species scale-driven breakdown of effective field theory in time-dependent string backgrounds
Alek Bedroya, Hayden Lee, Paul Steinhardt
We present a novel way in which effective field theory (EFT) can break down in cosmological string backgrounds depending on the behavior of the quantum gravity cutoff in infinite d…
TCC in the interior of moduli space and its implications for the string landscape and cosmology
Alek Bedroya, Qianshu Lu, Paul Steinhardt
We consider the classical Friedmann-Robertson-Walker solutions that describe a universe undergoing a transition from an accelerating expansion phase in the past to an eternal decel…