arXiv subjects

Conner Dailey

Publications and source records attributed to Conner Dailey.

9 recordsLinked to original sources

arXiv2026

Upwind embedded boundary SBP operators: New high order numerical schemes for arbitrarily shaped domains with Cartesian grids

Embedded boundary summation by parts (SBP) methods define finite differencing based derivative operators with the added feature that the boundary need not coincide with a grid cell, allowing a boundary to be embedded on a regular Cartesian grid. This is achieved by the introduction of interpolation/extrapolation operators that match the accuracy of the boundary closure. These methods have been used to perform black hole excision simulations on a domain with a spherical boundary embedded in a regular Cartesian grid, demonstrating their usefulness for nonlinear problems. In this work, new operators are derived using this embedded boundary framework to increase the order of accuracy of the interior and boundary closure while minimizing the boundary error. Additionally, these novel operators improve the spectral properties on the grid by generalizing to an upwind scheme that has better dispersion relation preserving properties compared to traditional SBP schemes for wave equations. These operators are tested with the curvilinear scalar wave equation on a 3D multiblock grid with an excision sphere embedded in the center block to demonstrate the robustness and accuracy of these novel embedded operators.

gr-qc↗

arXiv2024

Formulating the complete initial boundary value problem in numerical relativity to model black hole echoes

In an attempt to simulate black hole echoes (generated by potential quantum-gravitational structure) in numerical relativity, we recently described how to implement a reflecting boundary outside of the horizon of a black hole in spherical symmetry. Here, we generalize this approach to spacetimes with no symmetries and implement it numerically using the generalized harmonic formulation. We cast the evolution equations and the numerical implementation into a Summation By Parts (SBP) scheme, which seats our method closer to a class of provably numerically stable systems. We implement an embedded boundary numerical framework that allows for arbitrarily shaped domains on a rectangular grid and even boundaries that evolve and move across the grid. As a demonstration of this framework, we study the evolution of gravitational wave scattering off a boundary either inside, or just outside, the horizon of a black hole. This marks a big leap toward the goal of a generic framework to obtain gravitational waveforms for behaviors motivated by quantum gravity near the horizons of merging black holes.

gr-qc↗

arXiv2023

Detecting cosmological scalar fields using orbital networks of quantum sensors

In this Letter, we propose to detect the interaction of a hypothetical coherently evolving cosmological scalar field with an orbital network of quantum sensors, focusing on the GPS satellite network as a test example. Cosmological scenarios, such as a scalar-tensor theory for dark energy or the axi-Higgs model, suggest that such a field may exist. As this field would be (approximately) at rest in the CMB frame, it would exhibit a dipole as a result of the movement of our terrestrial observers relative to the CMB. While the current sensitivity of the GPS network is insufficient to detect a cosmological dipole, future networks of quantum sensors on heliocentric orbits, using state-of-the-art atomic clocks, can reach and exceed this requirement.

gr-qc↗

arXiv2023

Reflecting boundary conditions in numerical relativity as a model for black hole echoes

Recently, there has been much interest in black hole echoes, based on the idea that there may be some mechanism (e.g., from quantum gravity) that waves/fields falling into a black hole could partially reflect off of an interface before reaching the horizon. There does not seem to be a good understanding of how to properly model a reflecting surface in numerical relativity, as the vast majority of the literature avoids the implementation of artificial boundaries, or applies transmitting boundary conditions. Here, we present a framework for reflecting a scalar field in a fully dynamical spherically symmetric spacetime, and implement it numerically. We study the evolution of a wave packet in this situation and its numerical convergence, including when the location of a reflecting boundary is very close to the horizon of a black hole. This opens the door to model exotic near-horizon physics within full numerical relativity.

gr-qc↗

arXiv2021

Reply to the comment on ''Quantum sensor networks as exotic field telescopes for multi-messenger astronomy''

The comment by Stadnik [arXiv:2111.14351v1] claims that "back-action", i.e. interaction of exotic low-mass fields (ELF) with ordinary matter, "prevents the multi-messenger astronomy on human timescales." We strongly disagree with this blanket claim. This is {\em not a general conclusion}, as Stadnik's statement entirely relies on a specific sign of the ELF-matter interaction. As we demonstrate, there are coupling constant ranges when, in fact, the screening effects are irrelevant. In addition, the delay between the arrival of the ELF and gravitational wave bursts is reduced by the ELF-ordinary matter interaction, improving the discovery reach of our proposed novel, exotic physics, modality in multi-messenger astronomy.

gr-qc↗

arXiv2021

Search for topological defect dark matter with a global network of optical magnetometers

Ultralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the form of topological defects that could concentrate the dark matter density into many distinct, compact spatial regions that are small compared to the galaxy but much larger than the Earth. Here, we report the results of a search for transient signals from axion-like particle domain walls with the Global Network of Optical Magnetometers for Exotic physics searches (GNOME). We search the data, consisting of correlated measurements from optical atomic magnetometers located in laboratories all over the world, for patterns of signals propagating through the network consistent with domain walls. The analysis of data from a continuous month-long operation of the GNOME finds no statistically significant signals, thus placing experimental constraints on such dark matter scenarios.

astro-ph.CO↗

arXiv2020

Quantum sensor networks as exotic field telescopes for multi-messenger astronomy

Multi-messenger astronomy, the coordinated observation of different classes of signals originating from the same astrophysical event, provides a wealth of information about astrophysical processes with far-reaching implications. So far, the focus of multi-messenger astronomy has been the search for conventional signals from known fundamental forces and standard model particles, like gravitational waves (GW). In addition to these known effects, quantum sensor networks could be used to search for astrophysical signals predicted by beyond-standard-model (BSM) theories. Exotic bosonic fields are ubiquitous features of BSM theories and appear while seeking to understand the nature of dark matter and dark energy and solve the hierarchy and strong CP problems. We consider the case where high-energy astrophysical events could produce intense bursts of exotic low-mass fields (ELFs). We propose to expand the toolbox of multi-messenger astronomy to include networks of precision quantum sensors that by design are shielded from or insensitive to conventional standard-model physics signals. We estimate ELF signal amplitudes, delays, rates, and distances of GW sources to which global networks of atomic magnetometers and atomic clocks could be sensitive. We find that, indeed, such precision quantum sensor networks can function as ELF telescopes to detect signals from sources generating ELF bursts of sufficient intensity. Thus ELFs, if they exist, could act as additional messengers for astrophysical events.

astro-ph.IM↗

arXiv2019

Novel approaches to dark-matter detection using space-time separated clocks

We discuss the theoretical analysis and interpretation of space-time separated clock experiments in the context of a space-time varying scalar field that is non-universally coupled to the standard model fields. If massive, such a field is a candidate for dark matter and could be detected in laboratory experiments. We show that space-time separated experiments have the potential to probe a fundamentally different parameter space from more common co-located experiments, allowing decorrelation of previously necessarily correlated parameters. Finally, we describe such a space-time separated clock experiment currently running at the Paris Observatory, and present some preliminary results as a proof of principle.

gr-qc↗

arXiv2017

Search for domain wall dark matter with atomic clocks on board global positioning system satellites

Cosmological observations indicate that 85% of all matter in the Universe is dark matter (DM), yet its microscopic composition remains a mystery. One hypothesis is that DM arises from ultralight quantum fields that form macroscopic objects such as topological defects. Here we use GPS as a ~ 50,000 km aperture DM detector to search for such defects in the form of domain walls. GPS navigation relies on precision timing signals furnished by atomic clocks hosted on board GPS satellites. As the Earth moves through the galactic DM halo, interactions with topological defects could cause atomic clock glitches that propagate through the GPS satellite constellation at galactic velocities ~ 300 km/s. Mining 16 years of archival GPS data, we find no evidence for DM in the form of domain walls at our current sensitivity level. This allows us to improve the limits on certain quadratic scalar couplings of domain wall DM to standard model particles by several orders of magnitude.

hep-ph↗