Classical and Quantum Gravity最新文献

{"title":"Unifying the Regge-Wheeler-Zerilli and Bardeen-Press-Teukolsky formalisms on spherical backgrounds","authors":"David Pereñiguez","doi":"10.1088/1361-6382/aea1d1","DOIUrl":"https://doi.org/10.1088/1361-6382/aea1d1","url":null,"abstract":"Abstract We develop a formulation of perturbation theory on spherically symmetric backgrounds based on self-dual curvature equations combined with spherical harmonic expansions. The resulting framework unifies the Regge-Wheeler-Zerilli (RWZ) and Bardeen-Press-Teukolsky (BPT) formalisms and is designed to combine key advantages of both. The use of self-dual variables is crucial, and makes quasinormal mode isospectrality manifest, when present. We present the formalism first for a general energy-momentum tensor, and then specialize to vacuum General Relativity with matter sources to illustrate its practical advantages. A central result is that the RWZ and BPT equations arise directly as different components of a single tensorial curvature equation. We also show that, in the frequency domain, the metric can be reconstructed algebraically from any of the proposed master functions and their derivatives, and we comment on possible obstructions to such a reconstruction in the time domain. A Mathematica notebook, based on xAct, that implements the formalism and was used in our computations is released alongside this work.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"59 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing allowed complex metrics from black holes","authors":"Oscar Loaiza-Brito,J L López-Picón,Octavio Obregón","doi":"10.1088/1361-6382/ae9ae8","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9ae8","url":null,"abstract":"Abstract We use diffeomorphic mappings to connect black hole metrics with complex solutions allowed by the Kontsevich–Segal (KS) criterion. By swapping radial and time-like coordinates and applying complex mappings, we derive dynamic metrics sufficiently well-defined for a quantum field theory. This is shown for static and rotating black holes, mapping their interiors into the Kantowski–Sachs and a specific Gowdy-type cosmological model. We offer interpretations of the period during which the KS criterion holds.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"51 1","pages":"175008"},"PeriodicalIF":3.5,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Curvature conditions for generalized singularity theorems","authors":"Jeremías Daín,Gustavo Dotti","doi":"10.1088/1361-6382/ae9a26","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9a26","url":null,"abstract":"Abstract We study the curvature conditions introduced in Galloway and Senovilla (2010 Class. Quant. Grav. 27 152002) to predict focal points for trapped spacelike submanifolds in spacetimes of arbitrary dimensions, with the purpose of generalizing Penrose’s singularity theorem to compact trapped submanifolds (CTMs) of codimension higher than two. We find that these conditions do not apply in general but may apply for specific CTMs. As a result, higher codimension CTMs may still work as singularity predictors, although the possibility that they intersect the domain of outer communications cannot be ruled out using standard arguments.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"3 1","pages":"175001"},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core collapse supernova modeling: the next ten years","authors":"Anthony Mezzacappa","doi":"10.1088/1361-6382/ae9aea","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9aea","url":null,"abstract":"Abstract Core collapse supernova modeling has advanced considerably since the first numerical simulations were performed sixty years ago. In particular, the last decade has brought us sophisticated three-dimensional models with significant predictive capabilities—e.g. for core collapse supernova gravitational wave emission. The six decades of modeling have shown us the importance of individual components of these general relativistic neutrino radiation magnetohydrodynamics events—specifically, the importance of neutrino kinetics, fluid instabilities, magnetic fields, strong gravity, and the nuclear equation of state and neutrino–matter interactions calculated in a manner consistent with the equation of state. They have also shown us that simulation outcomes are sensitive to variations in the treatment of these ingredients, demanding a level of rigor that has not yet been consistently met by modelers. The efficacy of the neutrino shock reheating mechanism for core collapse supernovae has been demonstrated. The models now require an improved quantitative predictive capability, which will be achieved through increased sophistication in the treatment of model components, both macroscopic (e.g. strong-field gravity) and microscopic (e.g. neutrino–matter interactions). Advancement of core collapse supernova theory will also require the cooperation of modelers in other fields, especially stellar evolution and nuclear theory, to meet the level of rigor required to make the most of the eventuality of a galactic core collapse supernova and its multimessenger emissions.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"4 1","pages":"173001"},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A demonstration that classical gravity does not produce entanglement","authors":"Mike D Schneider,Nick Huggett,Niels Linnemann","doi":"10.1088/1361-6382/ae6f62","DOIUrl":"https://doi.org/10.1088/1361-6382/ae6f62","url":null,"abstract":"Abstract Once again, dispute has arisen over the interpretation of proposed quantum information theory experiments to probe the quantum nature of gravity by testing for gravitationally induced entanglement (GIE) between two spatially separated massive particles. The confusion appears to reside in interpreting applications of a Hamiltonian formalism. But classical gravity cannot mediate entanglement on independent grounds. A Newton–Cartan analysis shows that if gravity is classical, a mediator, and entanglement is observed as an outcome of performing a GIE experiment, something other than gravity must have supplied the (virtual) force needed during the experiment to produce the effect.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"53 1","pages":"177001"},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semiclassical phases of charged spin-\u0000 \u0000 \u0000 \u0000 \u0000 1\u0000 2\u0000 \u0000 \u0000 \u0000 \u0000 matter-wave interferometers in gravitational-wave backgrounds","authors":"Nontapat Wanwieng,Apimook Watcharangkool","doi":"10.1088/1361-6382/ae9a25","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9a25","url":null,"abstract":"Abstract A matter wave propagating through curved spacetime accumulates a phase that encodes both geometry and gauge structure. We develop a semiclassical description of charged spin- 1 2 matter-wave interferometry based on a WKB expansion of the general covariant Dirac equation. At leading order, and within the guided-arm approximation, the interferometric phase separates into three additive contributions: a dynamical phase associated with proper-time evolution, a spin phase arising from parallel transport in the local Lorentz frame, and an electromagnetic phase generated by curvature-induced perturbations of a background electromagnetic field. In a freely falling detector frame described by Fermi normal coordinates, the dynamical and spin channels are driven by the local gravitoelectric and gravitomagnetic tidal fields, while the electromagnetic channel follows from solving the detector-frame Maxwell equations for a uniform background magnetic field in the long-wavelength regime. For a weak gravitational wave (GW), all three channels are controlled by the common tidal scale h ¨ + , × ∼ Ω gw 2 h 0 , but enter through distinct couplings and geometry-dependent response kernels. Applied to an idealized square Mach–Zehnder interferometer, the dynamical channel reproduces the established tidal matter-wave response, and the spin channel is suppressed by the ratio of the Compton wavelength to the interferometer size. The electromagnetic channel is set by the applied magnetic flux rather than by the particle mass or spin: within the initial-value solution adopted here, its magnitude depends on the orientation of the background field relative to the wave, with the perpendicular configuration carrying an additional factor c / v , and the two orientations select different GW polarizations.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"201 1","pages":"175003"},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical derivation and verification of the amplitude of LISA’s interferometric signals on an ultra-stable interferometer testbed","authors":"Alvise Pizzella,Lennart Wissel,Miguel Dovale-Álvarez,Pablo Martínez Cano,Rodrigo García Álvarez,Christoph Bode,Juan José Esteban Delgado,Gerhard Heinzel","doi":"10.1088/1361-6382/ae98d6","DOIUrl":"https://doi.org/10.1088/1361-6382/ae98d6","url":null,"abstract":"Abstract The Laser Interferometer Space Antenna (LISA) mission aims to detect gravitational waves by interferometrically measuring the change of separation between free-falling test masses (TMs). LISA’s interferometers must deliver pm / Hz  sensitivity while accommodating beam tilts up to 1 mrad at the photodiodes (PDs), which degrade the interferometric amplitude and increase the induced readout noise coupling. This paper uses an analytical framework developed by the authors in a previous work, based on minimal and justified approximations, that relates beam tilt to the resulting heterodyne signal amplitude in a generic two-beam interferometer with circular-area PDs. A set of interferometric topologies is analyzed, all of high relevance for LISA. We derive the exact amplitude response for an infinite detector and a closed-form approximation for finite detectors, and we validate both against numerical simulations and experimental measurements on an ultra-stable LISA-representative testbed. We then use this model to quantify the phase-noise amplification arising from reduced signal-to-noise ratio under tilt, showing that curvature mismatches between the interfering beams substantially enhance this effect. Finally, we introduce a compact function that captures the angular dependence of correlated and uncorrelated phase noises in quadrant PD-based readouts. Here, a new noise feature, caused by wavefront curvature mismatch, is predicted and measured for the first time. These results indicate that controlling wavefront curvature mismatch in the TM interferometer is essential to limit excess phase noise. The models and results derived in this paper, although originating in the context of LISA, are general and can be applied to any interferometric topology undergoing tilts with pivot on the detector plane.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"16 1","pages":"175002"},"PeriodicalIF":3.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148894208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum gravity, de Sitter space, and normalizability","authors":"Stephon Alexander,Heliudson Bernardo,Jacob Kuntzleman,Max Pezzelle","doi":"10.1088/1361-6382/ae9819","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9819","url":null,"abstract":"Abstract We propose a resolution to the longstanding problem of perturbative normalizability in canonical quantum gravity of the Lorentzian Chern–Simons-Kodama (CSK) state with a positive cosmological constant in four dimensions. While the CSK state is an exact solution to the Hamiltonian constraint in the self-dual formulation and semiclassically describes de Sitter spacetime, its physical viability has been questioned due to apparent nonnormalizability and CPT asymmetry. Starting from a nonperturbative holomorphic inner product derived from the reality conditions of the self-dual Ashtekar variables (and using a dimensional regularization scheme to handle divergences), we show that the linearization, in terms of gravitons, of the CSK state is perturbatively normalizable for super-Planckian cosmological constant. Furthermore, we propose that a rotation in phase space, a generalization of Thiemann’s complexifier, can render the full perturbative state normalizable for all Λ by analytically continuing the non-convergent modes in phase space. This provides the first concrete realization of a CPT-breaking, yet normalizable, gravitational vacuum state rooted in a nonperturbative quantum gravity framework. Our results establish the CSK statelong thought formalas a viable candidate for the ground state of quantum gravity in de Sitter space.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"108 1","pages":"165025"},"PeriodicalIF":3.5,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing quantum scrambling and chaos in curved spacetime via Unruh-DeWitt detectors","authors":"M Y Abd-Rabbou","doi":"10.1088/1361-6382/ae9ae9","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9ae9","url":null,"abstract":"Abstract We introduce a local operational protocol for measuring quantum information scrambling in a curved spacetime background. In this framework, two Unruh-DeWitt (UDW) detectors, coupled to a massless conformally coupled scalar field in the Hartle–Hawking vacuum of the non-rotating ( 2 + 1 ) -dimensional Banados–Teitelboim–Zanelli (BTZ) black hole, serve as local probes. Evaluating the detector out-of-time-ordered correlator requires a fourth-order Dyson series expansion. Within the scrambling regime, this correlator exhibits exponential growth with Lyapunov exponent, exactly saturating the Maldacena–Shenker–Stanford bound at the global Hawking temperature. Governed by the black hole surface gravity, the Lyapunov exponent is universal and independent of detector positions, energy gaps, and coupling strengths. Furthermore, the scrambling amplitude shows a monotonic dependence on the radial positions of the detectors, vanishing at the event horizon and increasing outward. Local two-level probes thus witness the maximal chaos of the BTZ geometry without reconstructing the global quantum field state.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"18 1","pages":"165024"},"PeriodicalIF":3.5,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148895780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling acceleration without photon pair creation","authors":"Sara Kanzi,Daniel Hodgson,Almut Beige","doi":"10.1088/1361-6382/ae9aeb","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9aeb","url":null,"abstract":"Abstract The Unruh effect predicts that a uniformly accelerating observer will find themselves in a thermal bath of photons, where a resting observer would not see any. However, since Maxwell’s equations hold everywhere, the observers cannot tell who is resting and who is accelerating by looking only at the electromagnetic (EM) field. The only difference between different reference frames is that they use different spacetime coordinates; otherwise the formalism for the description of light must be the same for all observers. To provide new insight into the validity of the Unruh effect, this paper generalizes a recent physically-motivated quantization of the EM field to different reference frames. Afterward, we demonstrate that, in position space, an accelerating observer simply experiences a constantly changing Doppler effect, while all reference frames share a common vacuum.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"47 1","pages":"165023"},"PeriodicalIF":3.5,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}