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Your search keyword '"Kaiser, David A."' showing total 35 results
Start Over Author "Kaiser, David A." Publisher american physical society (aps)
35 results on '"Kaiser, David A."'

7. Primordial black holes from multifield inflation with nonminimal couplings

Author

Massachusetts Institute of Technology. Department of Physics, Geller, Sarah R, Qin, Wenzer, McDonough, Evan, Kaiser, David I, Massachusetts Institute of Technology. Department of Physics, Geller, Sarah R, Qin, Wenzer, McDonough, Evan, and Kaiser, David I

Abstract

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 high-energy physics -- including multiple interacting scalar fields and nonminimal couplings to the spacetime Ricci scalar -- that could produce PBHs with masses in the range required to address the present-day dark matter abundance. Such models are consistent with supersymmetric constructions, and only incorporate operators in the effective action that would be expected from generic effective field theory considerations. The models feature potentials with smooth large-field plateaus together with small-field features that can induce a brief phase of ultra-slow-roll evolution. Inflationary dynamics within this family of models yield predictions for observables in close agreement with recent measurements, such as the spectral index of primordial curvature perturbations and the ratio of power spectra for tensor to scalar perturbations. As in previous studies of PBH formation resulting from a period of ultra-slow-roll inflation, we find that at least one dimensionless parameter must be highly fine-tuned to produce PBHs in the relevant mass-range for dark matter. Nonetheless, we find that the models described here yield accurate predictions for a significant number of observable quantities using a smaller number of relevant free parameters.

Published
2022

9. Nonlinear Dynamics of Preheating after Multifield Inflation with Nonminimal Couplings

Author

Massachusetts Institute of Technology. Department of Physics, Kaiser, David I., Massachusetts Institute of Technology. Department of Physics, and Kaiser, David I.

Abstract

We study the postinflation dynamics of multifield models involving nonminimal couplings using lattice simulations to capture significant nonlinear effects like backreaction and rescattering. We measure the effective equation of state and typical timescales for the onset of thermalization, which could affect the usual mapping between predictions for primordial perturbation spectra and measurements of anisotropies in the cosmic microwave background radiation. For large values of the nonminimal coupling constants, we find efficient particle production that gives rise to nearly instantaneous preheating. Moreover, the strong single-field attractor behavior that was previously identified persists until the end of preheating, thereby suppressing typical signatures of multifield models. We therefore find that predictions for primordial observables in this class of models retain a close match to the latest observations., United States. Department of Energy (Contract DE-SC0012567)

Published
2020

14. Cosmic Bell Test Using Random Measurement Settings from High-Redshift Quasars

Author

Rauch, Dominik, primary, Handsteiner, Johannes, additional, Hochrainer, Armin, additional, Gallicchio, Jason, additional, Friedman, Andrew S., additional, Leung, Calvin, additional, Liu, Bo, additional, Bulla, Lukas, additional, Ecker, Sebastian, additional, Steinlechner, Fabian, additional, Ursin, Rupert, additional, Hu, Beili, additional, Leon, David, additional, Benn, Chris, additional, Ghedina, Adriano, additional, Cecconi, Massimo, additional, Guth, Alan H., additional, Kaiser, David I., additional, Scheidl, Thomas, additional, and Zeilinger, Anton, additional

Published
2018
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20. Cosmic Bell Test: Measurement Settings from Milky Way Stars

Author

Handsteiner, Johannes, primary, Friedman, Andrew S., additional, Rauch, Dominik, additional, Gallicchio, Jason, additional, Liu, Bo, additional, Hosp, Hannes, additional, Kofler, Johannes, additional, Bricher, David, additional, Fink, Matthias, additional, Leung, Calvin, additional, Mark, Anthony, additional, Nguyen, Hien T., additional, Sanders, Isabella, additional, Steinlechner, Fabian, additional, Ursin, Rupert, additional, Wengerowsky, Sören, additional, Guth, Alan H., additional, Kaiser, David I., additional, Scheidl, Thomas, additional, and Zeilinger, Anton, additional

Published
2017
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