449 citations · 1.7k across the 20 of their papers we have counts for
20 papers
Probing the Scale of ALP Interactions with Fermi Blazars
Rebecca Reesman, T. P. Walker
Gamma-rays from cosmological sources contain information about gamma-ray interactions. Standard model and non-standard model photon interactions along the path between the source a…
Anisotropies in the gamma-ray sky from millisecond pulsars
Jennifer M. Siegal-Gaskins, Rebecca Reesman, Vasiliki Pavlidou +2
Pulsars emerge in the Fermi era as a sizable population of gamma-ray sources. Millisecond pulsars (MSPs) constitute an older subpopulation whose sky distribution extends to high Ga…
Direct X-ray Constraints on Sterile Neutrino Warm Dark Matter
Casey R. Watson, John F. Beacom, Hasan Yuksel +1
Warm dark matter (WDM) might more easily account for small scale clustering measurements than the heavier particles typically invoked in Lambda cold dark matter (LCDM) cosmologies.…
The Concordance Cosmic Star Formation Rate: Implications from and for the Supernova Neutrino and Gamma Ray Backgrounds
Louis E. Strigari, John F. Beacom, Terry P. Walker +1
We constrain the Cosmic Star Formation Rate (CSFR) by requiring that massive stars produce the observed UV, optical, and IR light while at the same time not overproduce the Diffuse…
APS Neutrino Study: Report of the Neutrino Astrophysics and Cosmology Working Group
Steve W. Barwick, John F. Beacom, Vince Cianciolo +11
In 2002, Ray Davis and Masatoshi Koshiba were awarded the Nobel Prize in Physics ``for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos…
The Supernova Relic Neutrino Backgrounds at KamLAND and Super-Kamiokande
Louis E. Strigari, Manoj Kaplinghat, Gary Steigman +1
We calculate the Supernova Relic Neutrino (SRN) background flux for the KamLAND and Super-Kamiokande (SK) detectors, motivated by the reduction in background at SK and new results…
Big Bang Nucleosynthesis Constraints on Brane Cosmologies
Jonathan D. Bratt, A. C. Gault, Robert J. Scherrer +1
We examine constraints from Big Bang nucleosynthesis on type II Randall-Sundrum brane cosmologies with both a dark radiation component and a quadratic term that depends on the 5-di…
Constraints on the Cosmological Relativistic Energy Density
Andrew R. Zentner, Terry P. Walker
We discuss bounds on the cosmological relativistic energy density as a function of redshift, reviewing the big bang nucleosynthesis and cosmic microwave background bounds, updating…
Stellar Mixing and the Primordial Lithium Abundance
M. H. Pinsonneault, G. Steigman, T. P. Walker +1
We compare the properties of recent samples of the lithium abundances in halo stars to one another and to the predictions of theoretical models including rotational mixing, and we…
Production of A=6,7 Nuclides in the Alpha + Alpha Reaction and Cosmic Ray Nucleosynthesis
David J. Mercer, Sam M. Austin, J. A. Brown +6
Cross sections for production of 6He, 6Li, 7Li, and 7Be in the alpha+alpha reaction were measured at bombarding energies of 159.3, 279.6, and 619.8 MeV, and are found to decrease r…
How Does CMB + BBN Constrain New Physics?
James P. Kneller, Robert J. Scherrer, Gary Steigman +1
Recent cosmic microwave background (CMB) results from BOOMERANG, MAXIMA, and DASI provide cosmological constraints on new physics that can be competitive with those derived from Bi…
Cosmic Microwave Background constraint on residual annihilations of relic particles
Patrick McDonald, Robert J. Scherrer, Terry P. Walker
Energy injected into the Cosmic Microwave Background at redshifts z<10^6 will distort its spectrum permanently. In this paper we discuss the distortion caused by annihilations of r…
The Supernova Relic Neutrino Background
M. Kaplinghat, G. Steigman, T. P. Walker
An upper bound to the supernova relic neutrino background from all past Type II supernovae is obtained using observations of the Universal metal enrichment history. We show that an…
Nucleosynthesis in Power-Law Cosmologies
M. Kaplinghat, G. Steigman, T. P. Walker
We have recently considered cosmologies in which the Universal scale factor varies as a power of the age of the Universe and concluded that they cannot satisfy the observational co…
Primordial Nucleosynthesis: Theory and Observations
Keith A. Olive, Gary Steigman, Terry P. Walker
We review the Cosmology and Physics underlying Primordial Nucleosynthesis and survey current observational data in order to compare the predictions of Big Bang Nucleosynthesis with…
Constraining the cosmic abundance of stellar remnants with multi-TeV gamma-rays
David S. Graff, Katherine Freese, Terry Walker +1
If galactic halos contain stellar remnants, the infra-red flux from the remnant progenitors would contribute to the opacity of multi-TeV gamma-rays. The multi-TeV gamma-ray horizon…
Halo Star Lithium Depletion
M. H. Pinsonneault, T. P. Walker, G. Steigman +1
The depletion of lithium during the pre-main sequence and main sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynt…
The BBN Manifesto
Terry P. Walker
In this manifesto I review the status of standard BBN in light of recent observational data (e.g., QSO deuterium and Izotov etal. helium-4).
Big Bang Nucleosynthesis in Crisis?
N. Hata, R. J. Scherrer, G. Steigman +4
A new evaluation of the constraint on the number of light neutrino species (N_nu) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundance…
Predicting Big Bang Deuterium
N. Hata, R. J. Scherrer, G. Steigman +2
We present new upper and lower bounds to the primordial abundances of deuterium and helium-3 based on observational data from the solar system and the interstellar medium. Independ…