arXiv subjects

Douglas Singleton

Publications and source records attributed to Douglas Singleton.

At least 19 recordsLinked to original sources

arXiv2026

Signatures in the local interstellar medium of electromagnetic radiation produced by neutron star gravitational waves

The Voyager spacecraft have been detecting plasma oscillations of a few kHz for over 40 years. However, there is still no widely accepted hypothesis for the astrophysical source of the oscillations. Having entered the local interstellar medium, these detections have persisted, adding to the challenge of identifying the astrophysical source. Neutron stars were one of the earliest hypothesized candidates of the electromagnetic radiation responsible for the detected plasma oscillations, but no theoretical mechanism could be identified to explain the frequency of the oscillations. We explore the recently developed theory of co-production of electromagnetic radiation in gravitational wave backgrounds as a possible source of these low-frequency oscillations and investigate whether neutron stars could be the astrophysical source.

gr-qc↗

arXiv2026

Schwinger stability of T-duality-inspired extremal black holes

We study the near-horizon charged-scalar instability associated with Schwinger pair production in the charged regular black hole geometry of the zero-point-length T-duality prescription. Using the same effective geometry and regularized gauge potential, we construct the extremal branch, its ${\rm AdS}_2 \times S^2$ near-horizon throat, and the charged-scalar instability threshold for a general form factor. For the explicit T-duality form factor the extremal branch terminates at $r_\mathrm{ext} = \sqrt2 \, l_0$, where the extremal charge and the near-horizon electric field vanish while the ${\rm AdS}_2$ radius remains finite at $\sqrt3 \, l_0$. At this endpoint the exact near-horizon instability parameter is negative. In the semiclassical regime the corresponding charge-to-mass threshold diverges as the endpoint is approached. Thus, for each fixed massive species with finite $q/m$, a sufficiently near-endpoint portion of the extremal branch is free of the local charged-scalar instability. For comparison, the Ayón-Beato-García (ABG) Einstein-nonlinear-electrodynamics solution has a nonvanishing extremal near-horizon electric field. For an additional minimally coupled charged-scalar probe, the corresponding local Schwinger threshold remains finite. Thus the divergent near-endpoint Schwinger barrier found in the T-duality branch is not a generic consequence of regularity.

hep-th↗

arXiv2026

A regularized photon-pair geometry motivated by the ER=EPR conjecture

We regularize the Aichelburg-Sexl shock-wave geometry for massless particles by smearing the point-like source over a string-inspired length scale $l_0$. A radial extension of the transverse geometry admits a zero-throat Einstein-Rosen interpretation. For a photon wave packet of longitudinal extent $L$, the regularized gravitational self-energy of a transversely separated pair is $E_{\rm GSE}\sim \frac{4G(\hbarω)^2}{c^4L} \ln\!\left(\frac{d^2}{l_0^2}\right)$, where $d$ is the transverse separation. The factor $1/L$ strongly suppresses the interaction, giving gravitational stability times greater than $10^{30}$ years for optical photons. We also examine an effective two-dimensional entanglement-entropy description of the shock-wave geometry. The entropy construction reproduces the same dependence on the scales $d$, $L$, and $l_0$, and can be calibrated to reproduce the normalization of the direct self-energy calculation. However, we find that the gravitationally induced excess entropy, and hence the self-energy inferred from this prescription, is the same for Bell-entangled and unentangled photon pairs having identical energy-momentum distributions. This agrees with the direct geometrical calculation, since the classical two-shock metric depends on the stress-energy tensor but not on the polarization entanglement. The present construction should therefore be understood as a semiclassical ER-like geometry motivated by ER=EPR, rather than as a complete realization of the conjecture. A geometry whose connectivity tracks the amount of quantum entanglement would require a quantum-gravitational description sensitive to state-dependent correlations beyond the one-point stress-energy tensor.

gr-qc↗

arXiv2026

Regular black holes with gravitational self-energy as dark matter

We incorporate the effect of non-local gravitational self-energy to obtain a neutral, non-singular spacetime geometry. This is achieved by using a non-local gravitational theory inspired by T-duality, where particle mass is not point-like but smeared over a region. This non-local gravitational self-interaction is derived from the Newtonian gravitational potential and energy density, allowing us to define a coordinate-independent quantity. Thus, we incorporate the non-local gravitational field into the spacetime metric. We demonstrate that the total ADM mass is modified by a finite, regularized gravitational mass term, leading to a regular solution of the Ayon-Beato-Garcia type metric but without electric charge. We show the existence of extremal configurations known as \emph{particle-black hole} objects of order of the Planck mass, which are thermodynamically stable, have a vanishing Hawking temperature and could be a viable dark matter candidate.

gr-qc↗

arXiv2026

Spontaneous wave function collapse from non-local gravitational self-energy

We incorporate non-local gravitational self-energy, motivated by string-inspired T-duality, into the Schrödinger-Newton equation. In this framework spacetime has an intrinsic non-locality, rendering the standard linear superposition principle only an approximation valid in the absence of gravitational effects. We then invert the logic by assuming the validity of linear superposition and demonstrate that such superpositions inevitably become unstable once gravity is included. The resulting wave-function collapse arises from a fundamental tension between the equivalence principle and the quantum superposition principle in a semiclassical spacetime background. We further show that wave functions computed in inertial and freely falling frames differ by a gravitationally induced phase shift containing linear and cubic time contributions along with a constant global term. These corrections produce a global phase change and lead to a spontaneous, model-independent collapse time inversely proportional to the mass of the system.

gr-qc↗

arXiv2025

AC Stark effect or time-dependent Aharonov-Bohm effect for particle on a ring

We study the effect of a time-varying solenoidal vector potential for a quantum particle confined to a ring. The setup appears to be a time-varying version of the Aharonov-Bohm effect, but since the particle moves in the presence of fields, it is not strictly an Aharonov-Bohm effect. The results are similar to the ac Stark effect, but with a time-varying electric field coming from the vector potential, rather than the scalar potential. We compare and contrast the present effect with the standard ac Stark effect. The signature of this setup is the generation of quasi-energy sidebands which are observable via spectroscopy.

quant-ph↗

arXiv2025

Emergence of ER=EPR from non-local gravitational energy

We construct a class of wormhole geometries supported by the non-local gravitational self-energy that regularizes the particle and black-hole sectors of spacetime. Using this framework, inspired by T-duality, we show that two entangled particles (or particle-black-hole pairs) naturally source an Einstein-Rosen-type geometry in which the required violation of the strong energy condition arises from intrinsic quantum-gravity effects rather than from ad hoc exotic matter, which is matter that violates the null energy condition. We classify the resulting wormholes, analyze their horizons, throat structure and embedding properties, and we identify the exotic energy needed at the minimal surface. Imposing the ER=EPR requirement of non-traversability and the absence of a macroscopic throat, we find that only the zero-throat geometry is compatible with an entanglement-induced Einstein-Rosen bridge, providing a concrete realization of ER=EPR within a fully regular spacetime. Finally, we briefly discuss possible implications for microscopic ER networks from vacuum fluctuations, replica-wormhole interpretations of Hawking radiation, and possible links to entanglement-driven dark-energy scenarios.

gr-qc↗

arXiv2025

The Anholonomic Frame and Connection Deformation Method for constructing off-diagonal solutions in (modified) Einstein gravity and nonassociative geometric flows and Finsler-Lagrange-Hamilton theories

This article is a status report on the Anholonomic Frame and Connection Deformation Method, AFCDM, for constructing generic off-diagonal exact and parametric solutions in general relativity, GR, relativistic geometric flows, and modified gravity theories, MGTs. Such models can be generalized to nonassociative and noncommutative star products on phase spaces and modelled equivalently as nonassociative Finsler-Lagrange-Hamilton geometries. Our approach involves a nonholonomic geometric reformulation of classical models of gravitational and matter fields described by Lagrange and Hamilton densities on relativistic phase spaces. Using nonholonomic dyadic variables, the Einstein equations in GR and MGTs can be formulated as systems of nonlinear partial differential equations(PDEs), which can be decoupled and integrated in some general off-diagonal forms. In this approach, the Lagrange and Hamilton dynamics and related models of classical and quantum evolution are equivalently described in terms of generalized Finsler-like or canonical metrics and (nonlinear) connection structures on deformed phase spaces defined by solutions of modified Einstein equations. New classes of exact and parametric solutions in (nonassociative) MGTs are formulated in terms of generating and integration functions and generating effective/ matter sources. The physical interpretation of respective classes of solutions depends on the type of (non) linear symmetries, prescribed boundary/ asymptotic conditions, or posed Cauchy problems.

gr-qc↗

arXiv2025

GUP, Lorentz Invariance (Non)-Violation, and Non-Commutative Geometry

In this work, we formulate a generalized uncertainty principle with both position and momentum operators modified from their canonical forms. We study whether Lorentz symmetry is violated and whether it can be saved with these modifications. The requirement that Lorentz invariance is not violated places restrictions on the way the position and momentum operators can be modified. We also investigate the connection between general uncertainty principle and non-commutative geometry models, e.g.,laying out the connection between area/area operators and angular momentum in both models.

gr-qc↗

arXiv2025

Electromagnetic Field Momentum in Theoretical Magnetic Monopole-like Models

We show that some standard models of magnetic charge, the Banderet potential, the Dirac string potential, and the Wu-Yang fiber bundle approach, carry an electromagnetic field momentum in the presence of an electrostatic field. This electromagnetic field momentum suggests a violation of the center-of-energy theorem. We show that each of these monopole models also carry a hidden mechanical momentum, which saves the center-of-energy theorem.

hep-th↗

arXiv2025

Signatures of electromagnetic and sound radiation produced by gravitational waves in core-collapse supernovae

This paper presents the scenario that gravitational waves, generated in core-collapse of a pre-supernova star, can produce both electromagnetic radiation and sound radiation as gravitational waves propagate outward from the collapsing core. While the energy of this co-produced electromagnetic and sound radiation is orders of magnitude smaller than the initiating gravitational radiation, the power may be sufficient to re-ignite fusion outside the collapsing core. The non-equilibrium re-ignition of fusion, in roughly the same time frame as the strongest neutrino emissions, would change the configuration of the pre-supernova star and subsequently the ejecta and the evolution of the stellar expansion of the supernova remnant. Although the co-produced electromagnetic or sound radiation could not contribute directly to the supernova explosion, the associated non-equilibrium re-ignition of fusion would alter the state outside the core leaving an observable signature in the ejecta of the supernova remnant. The aim of this paper is to argue that including this hypothesized co-produced radiation in computational models of core collapse supernovae would contribute to the evolution of the stellar expansion and consequently should be observable in the supernovae remnant, providing a confirmation of the conversion processes for gravitational radiation to electromagnetic and sound radiation.

gr-qc↗

arXiv2024

Revisiting the Wu-Yang approach to magnetic charge

The Wu-Yang fiber bundle approach to magnetic charge is extended with a disk-like sheet current density and associated magnetic field in the overlap region between the Northern hemisphere and Southern hemisphere, where the different vector potentials connect. This disk magnetic field plays a role similar to the Dirac string in the Dirac approach to magnetic charge - it brings an inward magnetic flux of $4 πg$ which then gives rise to an outward Coulomb magnetic flux of $4 πg$. As with the Dirac string approach we show that placing an electric charge near this disk magnetic field gives rise to a non-zero electromagnetic field momentum. We discuss some of the possible physical consequences of this electromagnetic field momentum. We conclude by showing that the non-singular, but non-single valued Banderet monopole potential also has a disk-like magnetic flux and non-zero electromagnetic field momentum in the presence of an electric charge.

hep-th↗

arXiv2024

Topological interpretation of extremal and Davies-type phase transitions of black holes

Topological arguments are currently being used as a novel scheme to discern the properties of black holes while ignoring their detailed structure and specific field equations. Among various avenues of black hole physics, where this novel approach is being utilized, the phase transition in black hole thermodynamics lies at the forefront. There are several types of phase transition in black holes; such as the van der Waals type phase transition, Davies-type phase transition, extremal phase transition, and Hawking-Page (HP) transition. So far, the topological interpretation, where the critical point has been identified with the non-zero topological charge, has been obtained only for the van der Waals type phase transition and HP transition in different spacetimes. To complete the picture, here we provide the same interpretation for two other phase transitions: Davies-type phase transition and extremal phase transition. The entire analysis is general and is valid for any spacetime where these types of phase transitions are observed. More importantly, our analysis suggests that amid the apparent differences in these phase transitions, they share the same topological characteristics, \textit{i.e.} non-zero topological charge arising from different thermodynamic potentials in different types of phase transition.

gr-qc↗

arXiv2024

Nonassociative geometric and quantum information flows and R-flux deformations of wormhole solutions in string gravity

This article consists of an introduction to the theory of nonassociative geometric classical and quantum information flows defined by star products with R-flux deformations in string gravity. Corresponding nonassociative generalizations of the concepts of classical Shannon entropy, quantum von Neumann entropy, Rényi entropy are formulated. The fundamental geometric and quantum information objects are computed following the Grigori Perelman statistical thermodynamic approach to Ricci flows and gravity theories generalized for phase spaces modelled as (co) tangent Lorentz bundles. Nonassociative parametric deformations and nonholonomic thermo-geometric versions of statistical generating functions, their quantum analogues as density matrices are considered for deriving the entropy, energy and fluctuation functionals. This allows us to define and compute respective classical and quantum relative and conditional entropies, mutual information and nonassociative entanglement and thermodynamic information variables. We formulate the principles of nonassociative quantum geometric and information flow theory, QGIF, and study the basic properties of such quasi-stationary models related to modified gravity theories. Applications are considered for nonassociative deformed and entangled couples of four-dimensional, 4-d, wormholes (defined by respective spacetime and/or momentum type coordinates) and nonassociative QGIFs of 8-d phase space generalized wormholes configurations. Finally, we speculate on phase space black holes and wormholes being transversable for nonassociative qubits, quantum channels and entanglement witness; thought and laboratory experiments are discussed; and perspectives for quantum computer modelling and tests of nonassociative geometric flow and gravity theories are considered.

hep-th↗

arXiv2023

Field momentum and the reality of the Dirac String

It is well known that a magnetic monopole-electric charge system carries an angular momentum in its electromagnetic fields. Here we show that in the Dirac string formulation of magnetic charge the monopole-electric charge system also carries a momentum in its electromagnetic fields. This overlooked field momentum arises from the Coulomb electric field of the electric charge and the solenoidal magnetic field of the Dirac string. This implies that the monopole-charge system must either: (i) carry a ``hidden momentum" in the string, indicating that the string is real, or (ii) that the monopole-charge system violates the center-of-energy theorem. The overall conclusion is that the Dirac monopole with a {\it regulated} Dirac string is not a true monopole, and is not even a good effective description for topological monopoles ({\it e.g.} the 't Hooft-Polyakov monopole outside the core).

hep-th↗

arXiv2023

Quantum gravity, the cosmological constant, and parity transformation

One of the leading issues in quantum field theory and cosmology is the mismatch between the observed and calculated values for the cosmological constant in Einstein's field equations of up to 120 orders of magnitude. In this paper, we discuss new methods to potentially bridge this chasm using the generalized uncertainty principle (GUP). We find that if quantum gravity GUP models are the solution to this puzzle, then it may require the gravitationally modified position operator undergo a parity transformation at high energies.

gr-qc↗

arXiv2023

A new look at the Dirac quantization condition

The angular momentum of any quantum system should be {\it unambiguously} quantized. We show that such a quantization fails for a pure Dirac monopole due to a previously overlooked field angular momentum from the monopole-electric charge system coming from the magnetic field of the Dirac string and the electric field of the charge. Applying the point-splitting method to the monopole-charge system yields a total angular momentum which obeys the standard angular momentum algebra, but which is gauge {\it variant}. In contrast it is possible to properly quantize the angular momentum of a topological 't Hooft-Polyakov monopole plus charge. This implies that pure Dirac monopoles are not viable -- only 't Hooft-Polyakov monopoles are theoretically consistent with angular momentum quantization and gauge invariance.

hep-th↗

arXiv2023

Gravito-optics and intensity correlations for binary inspiral signal detections

We examine the correlation functions associated with intensity interferometry and gravito-optics of gravitational wave signals from compact binary coalescences. Previous theoretical studies of the gravito-optics of gravitational waves has concentrated on the characterization of both the classical and the non-classical properties of signals from cosmological sources in the early Universe. These previous works assume a periodic signal similar to the signals studied widely in optics and quantum optics and do not apply to transient signals. We develop the gravito-optics of intensity correlations for descriptions of the detection of transient signals from compact binary coalescences and apply these methods to calculate the two-point intensity correlations for the gravitational wave discovery. We also discuss the necessary theoretical work required for the description of the quantum gravito-optics of intensity correlations in the detection of signals from binary inspirals.

gr-qc↗