251 citations · 1.9k across the 44 of their papers we have counts for
23 papers · 1 filter
Quadratic Axion Couplings in String Theory
Naman Agarwal, Andrew R. Frey, Ratul Mahanta +1
Axions and axion-like particles are a compelling candidate for physics beyond the standard model. While many axion searches are focused on the linear coupling to photons $θF \tilde…
Early Dark Energy in Type IIB String Theory
Michele Cicoli, Matteo Licheri, Ratul Mahanta +3
Early Dark Energy (EDE) is a promising model to resolve the Hubble Tension, that, informed by Cosmic Microwave Background data, features a generalization of the potential energy us…
Completely Dark Matter from Rapid-Turn Multifield Inflation
Edward W. Kolb, Andrew J. Long, Evan McDonough +1
We study cosmological gravitational particle production as applied to "rapid-turn" models of inflation involving two scalar fields. We are interested in the production of massive s…
Towards Early Dark Energy in String Theory
Evan McDonough, Marco Scalisi
Early Dark Energy (EDE) is a prominent model to resolve the Hubble tension, which employs a dynamical axion with a periodic potential. In this work, we take first steps towards the…
Primordial Black Holes from Multifield Inflation with Nonminimal Couplings
Sarah R. Geller, Wenzer Qin, Evan McDonough +1
Primordial black holes (PBHs) provide an exciting prospect for accounting for dark matter. In this paper, we consider inflationary models that incorporate realistic features from h…
The Gravitino Swampland Conjecture
Edward W. Kolb, Andrew J. Long, Evan McDonough
We extend the swampland from effective field theories (EFTs) inconsistent with quantum gravity to EFTs inconsistent with quantum supergravity. This enlarges the swampland to includ…
Catastrophic Production of Slow Gravitinos
Edward W. Kolb, Andrew J. Long, Evan McDonough
We study gravitational particle production of the massive spin- Rarita-Schwinger field, and its close relative, the gravitino, in FRW cosmological spacetimes. For masses light…
Nonminimal Couplings and the Forgotten Field of Axion Inflation
Evan McDonough, Alan H. Guth, David I. Kaiser
We study the multifield dynamics of axion models nonminimally coupled to gravity. As usual, we consider a canonical symmetry-breaking model in which the axion is the phase o…
The Cosmological Heavy Ion Collider: Fast Thermalization after Cosmic Inflation
Evan McDonough
Heavy-ion colliders have revealed the process of "fast thermalization". This experimental breakthrough has led to new theoretical tools to study the thermalization process at both…
Higher Spin Supersymmetry at the Cosmological Collider: Sculpting SUSY Rilles in the CMB
Stephon Alexander, S. James Gates, Leah Jenks +2
We study the imprint of higher spin supermultiplets on cosmological correlators, namely the non-Gaussianity of the cosmic microwave background. Supersymmetry is used as a guide to…
dS Vacua and the Swampland
Renata Kallosh, Andrei Linde, Evan McDonough +1
In this note we revisit some of the recent 10d and 4d arguments suggesting that uplifting of supersymmetric AdS vacua leads to flattening of the potential, preventing formation of…
4d models of dS uplift in KKLT
Renata Kallosh, Andrei Linde, Evan McDonough +1
It was shown in arXiv:1808.09428 that the modified 4d version of the KKLT model proposed in arXiv:1707.08678 is inconsistent for large values of the parameter advocated in arXi…
de Sitter Vacua with a Nilpotent Superfield
Renata Kallosh, Andrei Linde, Evan McDonough +1
We study the arguments given in [1] which suggest that the uplifting procedure in the KKLT construction is not valid. First we show that the modification of the SUSY breaking secto…
Quantum Corrections and the de Sitter Swampland Conjecture
Keshav Dasgupta, Maxim Emelin, Evan McDonough +1
Recently a swampland criterion has been proposed that rules out de Sitter vacua in string theory. Such a criterion should hold at all points in the field space and especially at po…
Observable Chiral Gravitational Waves from Inflation in String Theory
Evan McDonough, Stephon Alexander
We consider gravitational wave production during inflation in type IIB string theory, and the possibility of observable gravitational waves in small field inflation. We show that t…
Chiral Gravitational Waves and Baryon Superfluid Dark Matter
Stephon Alexander, Evan McDonough, David N. Spergel
We develop a unified model of darkgenesis and baryogenesis involving strongly interacting dark quarks, utilizing the gravitational anomaly of chiral gauge theories. In these models…
Inflation from Nilpotent Kähler Corrections
Evan McDonough, Marco Scalisi
We develop a new class of supergravity cosmological models where inflation is induced by terms in the Kähler potential which mix a nilpotent superfield with a chiral sector …
Preheating and Entropy Perturbations in Axion Monodromy Inflation
Evan McDonough, Hossein Bazrafshan Moghaddam, Robert H. Brandenberger
We study the preheating of gauge fields in a simple axion monodromy model and compute the induced entropy perturbations and their effect on the curvature fluctuations. We find that…
Fermions on the Anti-Brane: Higher Order Interactions and Spontaneously Broken Supersymmetry
Keshav Dasgupta, Maxim Emelin, Evan McDonough
It has been recently argued that inserting a probe anti-D3-brane in a flux background breaks supersymmetry spontaneously instead of explicitly, as previously thought. In this paper…
Non-Kahler Resolved Conifold, Localized Fluxes in M-Theory and Supersymmetry
Keshav Dasgupta, Maxim Emelin, Evan McDonough
The known supergravity solution for wrapped D5-branes on the two-cycle of a Kahler resolved conifold is in general ISD but not supersymmetric, with the supersymmetry being broken b…
Backreaction and Stochastic Effects in Single Field Inflation
Laurence Perreault Levasseur, Evan McDonough
The formalism of stochastic inflation is a powerful tool for analyzing the backreaction of cosmological perturbations, and making precise predictions for inflationary observables.…
de Sitter Vacua in Type IIB String Theory: Classical Solutions and Quantum Corrections
Keshav Dasgupta, Rhiannon Gwyn, Evan McDonough +2
We revisit the classical theory of ten-dimensional two-derivative gravity coupled to fluxes, scalar fields, D-branes, anti D-branes and Orientifold-planes. We show that such set-up…
Two Field Matter Bounce Cosmology
Yi-Fu Cai, Evan McDonough, Francis Duplessis +1
We re-examine the non-singular Matter Bounce scenario first developed in [arXiv:1206.2382], which starts with a matter-dominated period of contraction and transitions into an Ekpyr…