Search Publications
Three-body exchanges with primordial black holes
Sinha, Kuver; Bhalla, Badal; Lehmann, Benjamin V. +1 more
The abundance of massive primordial black holes has historically been constrained by dynamical probes. Since these objects can participate in hard few-body scattering processes, they can readily transfer energy to stellar systems and, in particular, disrupt wide binaries. However, disruption is not the only possible outcome of such few-body proces…
White dwarfs as a probe of exceptionally light QCD axions
Balkin, Reuven; Serra, Javi; Springmann, Konstantin +2 more
We study the effects of exceptionally light QCD axions on the stellar configuration of white dwarfs. At finite baryon density, the nonderivative coupling of the axion to nucleons displaces the axion from its in-vacuum minimum, which implies a reduction of the nucleon mass. This dramatically alters the composition of stellar remnants. In particular…
Hubble tension or distance ladder crisis?
Perivolaropoulos, Leandros
We present an up-to-date compilation of published Hubble constant (
New bounds on light millicharged particles from the tip of the red-giant branch
Vincent, Aaron C.; Schutz, Katelin; Fung, Audrey +3 more
Stellar energy loss is a sensitive probe of light, weakly coupled dark sectors, including ones containing millicharged particles (MCPs). The emission of MCPs can affect stellar evolution and therefore can alter the observed properties of stellar populations. In this work, we improve upon the accuracy of existing stellar limits on MCPs by self-cons…
Searching for electromagnetic emission in an AGN from the gravitational wave binary black hole merger candidate S230922g
Valdes, Francisco; Andreoni, Igor; Graham, Matthew J. +18 more
We carried out long-term monitoring of the LIGO/Virgo/KAGRA binary black hole (BBH) merger candidate S230922g in search of electromagnetic emission from the interaction of the merger remnant with an embedding active galactic nuclei (AGN) accretion disk. Using a dataset primarily composed of wide-field imaging from the Dark Energy Camera and supple…
Nontensorial gravitational wave polarizations from the tensorial degrees of freedom: Linearized Lorentz-violating theory of gravity
Zhu, Zong-Hong; Hou, Shaoqi; Zhu, Tao +1 more
General relativity predicts the existence of only two tensorial gravitational wave polarizations, while a generic metric theory of gravity can possess up to four additional polarizations, including two vectors and two scalar ones. These vector/scalar polarizations are in general generated by the intrinsic new vector/scalar degrees of freedom of th…
Astrometric search for ultralight dark matter
Kim, Hyungjin
Precision astrometry offers a way to probe new physics. By measuring the angular position of light sources at unprecedented precision, astrometry could probe minuscule fluctuations of underlying spacetime. This work explores the possibility of probing ultralight dark matter candidates using precision astrometry. Through the coherent and stochastic…
Galactic structure from binary pulsar accelerations: Beyond smooth models
Chang, Philip; Widrow, Lawrence M.; Lam, Michael T. +3 more
We measure the line-of-sight accelerations of 26 binary pulsars due to the Milky Way's gravitational potential, and produce a three-dimensional map of the acceleration field of the Galaxy. Acceleration measurements directly give us the change in the line-of-sight velocity at present day, without requiring any assumptions inherent to kinematic mode…
Pulsar-based map of galactic acceleration
Moran, Abigail; Mingarelli, Chiara M. F.; Van Tilburg, Ken +1 more
Binary pulsars can be used to probe Galactic potential gradients through calculating their line-of-sight accelerations. We present the first data release of direct line-of-sight acceleration measurements for 29 binary pulsars. We validate these data with a local acceleration model, and compare our results to those from earlier works. We find evide…
Detection of gravitational waves in circular particle accelerators II. Response analysis and parameter estimation using synthetic data
Brüggen, Marcus; Rao, Suvrat; Baumgarten, Julia +1 more
We simulate the response of a Storage Ring Gravitational Wave Observatory (SRGO) to astrophysical millihertz (mHz) gravitational waves (GWs), numerically obtaining its sensitivity curve and optimal choices for some controllable experiment parameters. We also generate synthetic noisy GW data and use Markov Chain Monte Carlo methods to perform param…