arXiv subjects

Shaun David Brocus Fell

Publications and source records attributed to Shaun David Brocus Fell.

5 recordsLinked to original sources

arXiv2026

Radiative Signatures from Warp Drives Traveling Through the Earth's Atmosphere

We investigate the observable signatures of zero ADM mass warp drive spacetimes traversing Earth's atmosphere. Numerical simulations indicate that an aircraft-scale spacetime bubble moving at relativistic velocities would have a pronounced observational signature, where interaction with the atmosphere can produce luminosities exceeding one terawatt. The signature of a spacetime bubble at rest or moving at low velocity relative to the Earth would not generate such extreme luminosities. These results establish observational constraints on spacetime-based propulsion operating within the terrestrial environment and provide a framework for identifying potential high-velocity signatures. In particular, a warp drive traveling through the atmosphere at speeds exceeding approximately 10% of the speed of light would produce a unique brilliant glow.

gr-qc↗

arXiv2026

Empirical Evidence of Planetary Group Configurations Modulating Solar Activity

Our prior research found that a $90^{\circ}$ configuration of two planetary groups were temporally associated with significant changes in global electromagnetic standing waves (Schumann resonances) during and after the three $90^{\circ}$ configuration events occurring in late 2017 and early 2018. Specifically noted were reductions in variability moving into an event and level changes immediately after a event. Because global standing-wave data have a short history and no $90^{\circ}$ events have occurred since that period, we examine here whether these geometric configuration events correspond to similar signatures in the long sunspot count record. Using daily sunspot data from January 1935 through December 2024, we conducted empirical studies assessing variance changes, post-event level shifts, and potential intrinsic oscillatory structure. In Study A, a variance-ratio test showed that sunspot variability was systematically lower during the events than in the preceding period, with 21 of 26 events since 1935 exhibiting reduced variance (binomial $p=0.0025$). In Study B, solar activity level declined roughly 21 days after events ended, with 21 of 26 events showing negative changes (binomial $p=0.0025$). In Study C, wavelet and filtering analyses revealed no internal solar oscillations at comparable timescales. These findings provide empirical evidence that the configuration events are associated with shifts in solar activity. The next three configuration events in mid- and late-2026 offer an opportunity to assess these patterns in real time.

astro-ph.SR↗

arXiv2024

Proca in an Expanding Universe

The superradiant growth of massive vector fields in rotating black hole spacetimes has garnered significant attention in recent literature. However, the majority of these studies overlook the influence of a cosmological constant, which likely constitutes the primary energy content of our universe. In this paper, we extend recent research by incorporating a cosmological constant into the Einstein+Proca system and numerically evolving the resulting equations of motion. Utilizing the newly released GRBoondi numerical relativity code, designed specifically for the numerical evolution of (generalized) Proca fields, we discover that parameters causing a growing instability in the $Λ= 0$ scenario transition to a decaying state when $Λ> 0$. This results in a more intriguing phenomenology. These simulations pave the way for future full Einstein+Proca simulations to explore the secular decay of the resultant cloud from gravitational emission.

gr-qc↗

arXiv2024

GRBoondi: A code for evolving Generalized Proca theories on arbitrary backgrounds

While numerical simulations offer unparalleled precision and robustness in studying complex physical systems, their execution is often hindered by complexity, costliness, and time consumption due to the intricate equations involved. This challenge is already encountered in General Relativity, where non-flat spacetimes exacerbate the computational burden. This complexity is further intensified when dealing with additional degrees of freedom. To address this challenge head-on, we introduce GRBoondi, a groundbreaking fixed-background numerical relativity code designed to provide a unified interface for numerically solving Generalized Proca theories. GRBoondi grants users the ability to make arbitrary modifications to the Proca equations of motion on any background, providing a robust and versatile tool for exploring diverse classes of Generalized Proca theories. This letter serves as part of the submission of GRBoondi to the Journal of Open Source Software. For access to the code, please visit https://github.com/ShaunFell/GRBoondi.git.

gr-qc↗

arXiv2023

Detecting Fundamental Vector Fields with LISA

The advent of gravitational wave astronomy has seen a huge influx of new predictions for potential discoveries of beyond the Standard Model fields. The coupling of all fundamental fields to gravity, together with its dominance on large scales, makes gravitational physics a rich laboratory to study fundamental physics. This holds especially true for the search for the elusive dark photon, a promising dark matter candidate. The dark photon is predicted to generate instabilities in a rotating black hole spacetime, birthing a macroscopic Bose-Einstein condensate. These condensates can especially form around super massive black holes, modifying the dynamical inspiralling process. This then opens another window to leverage future space-borne gravitational wave antennas to join the hunt for the elusive dark matter particle. This study builds a preliminary model for the gravitational waveform emitted by such a dressed extreme mass-ratio inspiral. Comparing these waveforms to the vacuum scenario allows projections to the potential constrainability on the dark photon mass by space-borne gravitational wave antennas. The superradiant instability of a massive vector field on a Kerr background is calculated and, under reasonable approximations, the backreaction on the orbit of an inspiralling solar mass-scale compact object due to the secular evolution of the resulting boson cloud is determined. The end result is the projection that the LISA mission should be able to constrain the dark photon mass using extreme mass ratio inspirals in the range $[1.8 \times 10^{-17}, 4.47 \times 10^{-16}]$ eV.

gr-qc↗