Classical and Quantum Gravity最新文献

{"title":"Late-time cosmic acceleration from quantum gravity","authors":"Xiankai Pang and Daniele Oriti","doi":"10.1088/1361-6382/adecdb","DOIUrl":"https://doi.org/10.1088/1361-6382/adecdb","url":null,"abstract":"We deepen the analysis of the cosmological acceleration produced by quantum gravity dynamics in the formalism of group field theory condensate cosmology, treated at the coarse-grained level via a phenomenological model, in the language of hydrodynamics on minisuperspace. Specifically, we conduct a detailed analysis of the late-time evolution, which shows a phantom-like phase followed by an asymptotic De Sitter expansion. We argue that the model indicates a recent occurrence of the phantom crossing and we extract a more precise expression for the effective cosmological constant, linking its value to other parameters in the model and to the scale of the quantum bounce in the early Universe evolution. Additionally, we show how the phantom phase produced by our quantum gravity dynamics increases the inferred value of the current Hubble parameter based on observed data, indicating a possible quantum gravity mechanism for alleviating the Hubble tension. Our results represent a concrete example of how quantum gravity can provide an explanation for large-scale cosmological puzzles, in an emergent spacetime scenario.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"51 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677567","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":"The impact of local noise recorded at the ET candidate sites on the signal to noise ratio of CBC gravitational wave signals for the ET triangle configuration","authors":"Matteo Di Giovanni, Davide Rozza, Rosario De Rosa, Enrico Calloni, Domenico D’Urso, Luca Naticchioni, Annalisa Allocca, Giovanni Luca Cardello, Alessandro Cardini, Andrea Contu, Giovanni Diaferia, Luciano Errico, Carlo Giunchi, Jan Harms, Irene Molinari, Marco Olivieri, Piero Rapagnani, Valeria Sipala, Lucia Trozzo and Fulvio Ricci","doi":"10.1088/1361-6382/aded67","DOIUrl":"https://doi.org/10.1088/1361-6382/aded67","url":null,"abstract":"We present an evaluation of how site dependent noise can affect the signal to noise ratio (SNR) of compact binary coalescence (CBC) signals in the future 3rd generation gravitational wave (GW) detector Einstein telescope (ET). The design of ET is currently pushing the scientific community to study its scientific potential with respect to known, and possibly unexpected, GW signals using its design sensitivity curves. However, local ambient noise may have an impact on the ET sensitivity at low frequency and therefore affect the SNR of CBC signals at low frequency. Therefore, we study the impact of ambient noise on the ET sensitivity curve at the two sites candidate to host ET—Sardinia, in Italy, and the Euregio Meuse–Rhine (EMR) at the Netherlands–Belgium border—and infer the impact on the ET sensitivity curve and how the SNR of CBC signals at low frequencies is affected. We find that Sardinia shows results which are on par, if not better, than the design case. On the other hand, ambient noise for the current EMR sensitivity curve in Terziet causes a higher degradation of the SNR performances.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"12 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677286","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":"pp-waves and the hidden symmetries of black hole quasinormal modes","authors":"Daniel Kapec and Ahmed Sheta","doi":"10.1088/1361-6382/adecda","DOIUrl":"https://doi.org/10.1088/1361-6382/adecda","url":null,"abstract":"There are two interesting classes of trapped null geodesics in any black hole spacetime: those that lie on the photon ring and those that generate the horizon. Recent work introduced a ‘near-ring’ scaling limit that exhibits the emergent symmetries of the eikonal quasinormal mode (QNM) spectrum associated to the photon ring. This analysis was reformulated geometrically by Fransen using the Penrose limit, which produces pp-waves from geodesics. We elaborate on and generalize various aspects of this construction for the Schwarzschild black hole. We also discuss the Penrose limit onto the horizon generators. This second limit, although technically simpler, also displays emergent near-horizon symmetries that explain the equally-spaced overtones of the highly-damped QNM spectrum. In both examples, symmetry considerations distinguish the QNM solutions from the scattering states and produce overtones as descendants.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"25 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677566","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":"Gravitational quantum speed limit","authors":"Nicola Pranzini and Lorenzo Maccone","doi":"10.1088/1361-6382/adee70","DOIUrl":"https://doi.org/10.1088/1361-6382/adee70","url":null,"abstract":"While playing an important role in the foundations of quantum theory, Quantum Speed Limits (QSL) have no role in discussions about the search for quantum gravity. We fill this gap by analysing what QSL arises when superposing spherically symmetric masses in canonical quantum gravity. By this procedure, we find that the quantum mechanical Mandelstam–Tamm and Margolus–Levitin bounds can be improved by superposing a spherically symmetric, static and asymptotically flat spacetime between states with different ADM energies and mass densities. We discuss the feasibility and significance of measuring times via these superpositions.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"143 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669635","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":"Gravity from thermodynamics in vacuum: Lorentz invariance and the role of Bel–Robinson tensor","authors":"Ana Alonso-Serrano and Marek Liška","doi":"10.1088/1361-6382/adecd6","DOIUrl":"https://doi.org/10.1088/1361-6382/adecd6","url":null,"abstract":"Thermodynamics of local causal horizons has been shown to encode the information necessary to derive the equations governing the gravitational dynamics. We have previously argued that, in the presence of matter, this derivation further implies quantum phenomenological corrections to gravitational dynamics. Herein, we study whether similar corrections also occur in vacuum. We show that, under the assumptions of locality and local Lorentz invariance of physics, the vacuum dynamics is prescribed by the Einstein equations. We also discuss an alternative paradigm which assumes the existence of a preferred direction of time (much like in Einstein-aether or Hořava–Lifshitz gravity). Then, we find an modified gravitational dynamics in which Ricci curvature is sourced by Bel–Robinson super-energy.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"66 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669611","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 directed continuous-wave search from Scorpius X-1 with the five-vector resampling technique","authors":"Francesco Amicucci, Paola Leaci, Pia Astone, Sabrina D’Antonio, Stefano Dal Pra, Matteo Di Giovanni, Luca D’Onofrio, Federico Muciaccia, Cristiano Palomba, Lorenzo Pierini and Akshat Singhal","doi":"10.1088/1361-6382/adecd7","DOIUrl":"https://doi.org/10.1088/1361-6382/adecd7","url":null,"abstract":"Continuous gravitational-wave signals (CWs), which are typically emitted by rapidly rotating neutron stars with non-axisymmetric deformations, represent particularly intriguing targets for the Advanced Laser Interferometer GW Observatory (LIGO)-Virgo-KAGRA detectors. These detectors operate within sensitivity bands that encompass more than half of the known pulsars in our galaxy existing in binary systems (i.e. over 417 pulsars), which are the targeted sources of this paper. However, the detection of these faint signals is especially challenged by the Doppler modulation due to the source’s orbital motion, typically described by five Keplerian parameters, which must be determined with high precision to effectively detect the signal. This modulation spreads the signal across multiple frequency bins, resulting in a notable reduction of signal-to-noise ratio and potentially hindering signal detection. To overcome this issue, a robust five-vector resampling data-analysis algorithm has been developed to conduct thorough directed/narrowband CW searches at an affordable computational cost. We employ this methodology for the first time to search for CWs from Scorpius X-1 in a selected region of the parameter space, using publicly available data from the third observing run of the Advanced LIGO-Virgo-KAGRA detectors. No statistically significant CW signals can be claimed. Hence, we proceeded setting 95% confidence-level upper limits in selected frequency bands and orbital parameter ranges, while also evaluating overall sensitivity.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"17 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652230","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 Bogovskiǐ-type operator for Corvino–Schoen hyperbolic gluing","authors":"Piotr T Chruściel, Albachiara Cogo and Andrea Nützi","doi":"10.1088/1361-6382/adda88","DOIUrl":"https://doi.org/10.1088/1361-6382/adda88","url":null,"abstract":"We construct a solution operator for the linearized constant scalar curvature equation at hyperbolic space in dimension larger than or equal to two. The solution operator has good support propagation properties and gains two derivatives relative to standard norms. It can be used for Corvino–Schoen-type hyperbolic gluing, partly extending the recently introduced Mao–Oh–Tao gluing method to the hyperbolic setting.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"7 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652165","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":"Robust Bayesian inference with gapped LISA data using all-in-one TDI- ∞","authors":"Niklas Houba, Jean-Baptiste Bayle and Michele Vallisneri","doi":"10.1088/1361-6382/adeb3c","DOIUrl":"https://doi.org/10.1088/1361-6382/adeb3c","url":null,"abstract":"The Laser Interferometer Space Antenna (LISA), an European Space Agency L-class mission, is designed to detect gravitational waves in the millihertz frequency band, with operations expected to begin in the next decade. LISA will enable groundbreaking studies of astrophysical phenomena such as massive black hole mergers, extreme mass ratio inspirals, and compact binary systems. A key challenge in analyzing LISA’s data is the significant laser frequency noise, which must be suppressed using time-delay interferometry (TDI) during on-ground processing. Classical TDI mitigates this noise by algebraically combining phase measurements taken at different times and spacecraft. However, data gaps caused by instrumental issues or operational interruptions complicate the process. These gaps affect multiple TDI samples due to the time delays inherent to the algorithm, rendering surrounding measurements unusable for parameter inference and degrading overall data quality. In this paper, we apply the recently proposed variant of TDI known as TDI- to astrophysical parameter inference, focusing on the challenge posed by data gaps. TDI- frames the LISA likelihood numerically in terms of raw measurements, marginalizing over laser phase noises under the assumption of infinite noise variance. Additionally, TDI- is set up to incorporate and cancel other noise sources beyond laser noise, including optical bench motion, clock noise, and modulation noise, establishing it as an all-in-one TDI solution. The method gracefully handles measurement interruptions, removing the need to explicitly address discontinuities during gravitational-wave template matching. We integrate TDI- into a Bayesian framework, demonstrating its superior performance in scenarios involving data gaps. Compared to classical TDI, the method preserves signal integrity more effectively and is particularly interesting for low-latency applications, where the limited amount of available data makes data gaps particularly disruptive. The study’s results highlight the potential of TDI- to enhance LISA’s scientific capabilities, paving the way for more robust data analysis pipelines.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"208 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652166","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":"All-loop effective potential for arbitrary scalar models in curved space-time","authors":"V A Filippov, R M Iakhibbaev and D M Tolkachev","doi":"10.1088/1361-6382/adecd8","DOIUrl":"https://doi.org/10.1088/1361-6382/adecd8","url":null,"abstract":"In this paper we calculate the leading divergences of the effective potential for an arbitrary scalar theory on a curved spacetime background. Based on the recurrence relation between the leading poles following from the locality condition, we obtain a system of generalised renormalisation-group equations that can be studied numerically or analytically in some special cases. We study the simplest effective potentials for power-like models and give a comparison of them in the framework of cosmological phenomenology.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"12 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652231","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":"Dark energy due to quantum corrections to effective potential","authors":"V A Filippov, R M Iakhibbaev, D I Kazakov and D M Tolkachev","doi":"10.1088/1361-6382/adec34","DOIUrl":"https://doi.org/10.1088/1361-6382/adec34","url":null,"abstract":"In this paper we calculate quantum corrections to the effective potential in different models of inflationary cosmology. We show that quantum corrections lead to a modification of the initial potential uplifting its value at the minimum, which can be interpreted as a cosmological constant/dark energy. We concentrate on the models of α-attractors and show that one can naturally get small values of the cosmological constant. In the model of quintessence, the same mechanism modifies the value of dark energy at the present time.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"12 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144645252","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}