gr-qc papers | Gist.Science

Non-minimally coupled scalar field dark sector of the universe: in-depth (Einstein frame) case study

Motivated by recent DESI DR2 results suggesting evolving dark energy, this study analyzes spatially flat FLRW cosmological models with non-minimally coupled scalar fields in the Einstein frame, employing dynamical system methods to examine the evolution and stability of five specific scalar field models under various coupling parameters to understand energy transfer between the scalar sector and matter.

Marcin PostolakThu, 12 Ma⚛️ gr-qc

Superradiance in acoustic black hole

This paper theoretically and numerically demonstrates that acoustic black holes fabricated from solid materials exhibit superradiance under general conditions, though with significantly weaker amplification than regular cylinders due to material absorption, while also showing behavior consistent with extremal Kerr black holes and offering superior design flexibility.

Chengye Yu, Xiaolin Zhang, Sobhan Kazempour, Sichun SunThu, 12 Ma⚛️ gr-qc

Quiescent Big Bang formation in $2+1$ dimensions

This paper proves that $(2+1)$ -dimensional solutions to the Einstein scalar-field Vlasov system, initially close to FLRW spacetimes on closed surfaces of arbitrary genus, exhibit stable Big Bang singularities with quiescent, velocity-term-dominated asymptotics and $C^2$ -inextendibility, thereby establishing the Strong Cosmic Censorship conjecture for a corresponding class of polarized $U(1)$ -symmetric vacuum solutions.

Liam UrbanThu, 12 Ma⚛️ gr-qc

Existence of nonlinearly scalarized black holes in Einstein-scalar-Gauss-Bonnet theory with polynomial couplings

This paper investigates the existence and stability of nonlinearly scalarized black holes in Einstein-scalar-Gauss-Bonnet theory with polynomial couplings, demonstrating that while quartic-only couplings stabilize Schwarzschild black holes, specific higher-order polynomial couplings induce instability and transition to scalarized states above certain pulse thresholds, with the resulting solution branches exhibiting universal features in the probe limit but distinct dependencies on coupling strength when backreaction is included.

De-Cheng Zou, Xu Yang, Meng-Yun Lai, Hyat Huang, Bo Liu, Jutta Kunz, Yun Soo Myung, Rui-Hong YueThu, 12 Ma⚛️ gr-qc

Interacting dark sector from intrinsic entropy couplings

This paper introduces a new class of interacting dark sector models where dark matter's intrinsic entropy couples to scalar field dark energy, preserving the standard expansion history while generating distinctive, scale-dependent signatures in cosmological perturbations and structure growth that remain compatible with current observations.

Erik Jensko, Elsa M. Teixeira, Vivian PoulinThu, 12 Ma⚛️ gr-qc

Unexpectedly Weak General Relativistic Effects in Strongly Relativistic Tidal Disruption Events

Contrary to the prevailing belief that strong relativistic effects rapidly dissipate orbital energy to form prompt accretion disks, general relativistic hydrodynamic simulations reveal that even in strongly relativistic tidal disruption events, debris remains highly eccentric and extended with circularization occurring intrinsically slowly due to stream self-interactions that weaken relativistic shocks.

Ho-Sang Chan, Taeho Ryu, Julian Krolik, Tsvi PiranThu, 12 Ma⚛️ gr-qc

Kick matters: The impact of a new recoil model on the retention of hierarchical black-hole remnants in globular clusters

By employing a state-of-the-art recoil-kick model (gwModel_flow_prec) instead of traditional analytic approximations, this study demonstrates that the retention probability of hierarchical black-hole merger remnants in globular clusters is significantly higher, thereby altering the resulting mass and spin distributions and offering new insights into the formation of massive binaries like GW231123.

Tousif Islam, Digvijay Wadekar, Konstantinos KritosThu, 12 Ma🔭 astro-ph

Reduced phase space induced decay conditions

This paper proposes a reduced phase space approach to resolving the complex interplay between constraint structures and field decay conditions in gauge theories by parametrizing kinematical decay solely through the true degrees of freedom, thereby unambiguously determining the decay of gauge degrees of freedom via algebraic constraints and tailored gauge conditions.

Thomas ThiemannThu, 12 Ma⚛️ gr-qc

Thermal enhancement of inflationary magnetic fields

This paper proposes that assuming a thermal initial state for gauge fields during inflation, rather than the standard vacuum, introduces a dissipative boost that enhances primordial magnetic fields by up to $10^{16}$, suggesting that embedding this mechanism in a warm inflation framework offers a promising path to inflationary magnetogenesis without requiring non-minimal couplings or modified electrodynamics.

Arjun Berera, Suddhasattwa Brahma, Zizang Qiu, Rudnei O. RamosThu, 12 Ma🔭 astro-ph

Measuring neutrino mass in light of ACT DR6 and DESI DR2

This paper presents updated constraints on the total neutrino mass and its hierarchy across various cosmological models using ACT DR6, DESI DR2, and DESY5 data, revealing that while dark energy evolution significantly influences the tightness of upper limits, the inverted hierarchy consistently yields weaker constraints than the degenerate hierarchy.

Lu Feng, Tian-Nuo Li, Guo-Hong Du, Jing-Fei Zhang, Xin ZhangThu, 12 Ma⚛️ hep-ph

Holographic dark energy from a new two-parameter entropic functional

This paper proposes a new holographic dark energy model derived from a two-parameter generalized entropic functional, which naturally unifies standard holographic dark energy and $\Lambda$ CDM cosmology while successfully reproducing the matter-to-dark-energy transition and allowing for diverse dynamical behaviors like quintessence or phantom regimes.

G. G. Luciano, E. N. SaridakisThu, 12 Ma⚛️ gr-qc

Naturally Light Distortion

This paper demonstrates that within the most general formulation of gravity with independent metric and connection, a unique naturally light vector or scalar distortion field emerges as a dynamical degree of freedom, notably predicting a light scalar particle that mixes with the Higgs boson.

Kazunori NakayamaThu, 12 Ma⚛️ gr-qc

Production of Gravitational Waves in the Early Universe From turbulence triggered by first-order phase transitions

This paper investigates the production of primordial gravitational waves from first-order phase transitions in the early universe by modeling the resulting plasma turbulence with relativistic hydrodynamics and comparing two existing models against a new approach that incorporates freely decaying turbulence with a time-dependent de-coherence function.

Yashmitha KumaranThu, 12 Ma⚛️ gr-qc

Long-lived quasinormal modes, shadows and particle motion in four-dimensional quasi-topological gravity

This paper investigates massive scalar perturbations and particle motion in four-dimensional quasi-topological regular black holes, revealing that while photon and geodesic properties show only moderate deviations from Schwarzschild values, increasing scalar field mass leads to long-lived quasinormal modes and late-time power-law tails.

Bekir Can Lütfüo\u{g}luThu, 12 Ma⚛️ gr-qc

Bouncing singularities and thermal correlators on line defects

This paper confirms that both local operator and line defect displacement correlators in holographic thermal CFTs exhibit "bouncing singularities" linked to black hole interiors, demonstrating exact agreement between WKB and OPE analyses and proposing a factorization formula to describe deviations from this universal high-frequency structure.

Simone Giombi, Yue-Zhou Li, Jieru ShanThu, 12 Ma⚛️ hep-th

Energy extraction-driven instability and horizon formation in Kerr-Newman naked singularities and their limiting cases

This paper presents a unified analysis demonstrating that continuous rotational and electromagnetic energy extraction can drive over-extremal Kerr, Reissner-Nordström, and Kerr-Newman naked singularities toward the extremal bound over astrophysical timescales, potentially leading to horizon formation as a stabilizing mechanism.

Vishva PatelThu, 12 Ma⚛️ gr-qc

Nucleating an Inflationary Universe: Euclidean Wormholes and their No-Boundary Limit

This paper demonstrates that Euclidean wineglass wormholes and no-boundary instantons belong to a unified family of solutions connected by a zero-charge limit, resolving the puzzle of negative wormhole actions and revealing that while no-boundary instantons dominate the probability distribution, small-charge wormholes favor longer inflationary phases.

George Lavrelashvili, Jean-Luc LehnersThu, 12 Ma⚛️ hep-th

Gauss-Bonnet scalarization of charged qOS-black holes

This paper investigates the Gauss-Bonnet scalarization of charged quantum Oppenheimer-Snyder black holes within Einstein-Gauss-Bonnet-scalar theory coupled to nonlinear electrodynamics, demonstrating that while positive coupling allows scalarization for specific parameters, negative coupling induces a distinct, linearly stable scalarization mechanism within a narrow range of the action parameter.

Hong Guo, Wontae Kim, Yun Soo MyungThu, 12 Ma⚛️ gr-qc

On the angular localization of gravitational-wave signals by pulsar timing arrays

This paper provides a comprehensive analytical study of gravitational-wave signal localization by pulsar timing arrays, deriving expressions for sky localization precision that reveal how the interplay between pulsar-source angular proximity and distance measurement accuracy determines whether improvements stem from tighter distance constraints or the strategic addition of nearby pulsars.

Stephen R. TaylorThu, 12 Ma🔭 astro-ph

Thermodynamically massless Simpson-Visser black holes

This paper demonstrates that within Einstein gravity coupled to nonlinear electrodynamics and a phantom scalar field, the Simpson-Visser regular black hole possesses a vanishing thermodynamic mass due to boundary contributions, yet remains thermodynamically less favorable than its singular counterpart when compared under identical thermal and magnetic conditions.

Thanasis Karakasis, Emmanuel N. Saridakis, Zi-Yu TangThu, 12 Ma⚛️ gr-qc

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