General Relativity and Quantum Cosmology
New submissions
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New submissions for Fri, 1 Mar 24
 [1] arXiv:2402.18604 [pdf, other]

Title: Dynamics of holographic dark energy with apparenthorizon cutoff and nonminimal derivative coupling gravity in nonflat FLRW universeAuthors: Amornthep Tita (NAS Mahidol U. and IF Naresuan U.), Burin Gumjudpai (NAS Mahidol U.), Pornrad Srisawad (Dept. of Physics, Naresuan U.)Comments: 15 pages, 4 figuresSubjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO)
Background cosmological dynamics for a universe with matter, a scalar field nonminimally derivative coupling to Einstein tensor under powerlaw potential and holographic vacuum energy is considered here. The holographic IR cutoff scale is apparent horizon which, for accelerating universe, forms a trapped null surface in the same spirit as blackhole's event horizon. For nonflat case, effective gravitational constant can not be expressed in the Friedmann equation. Therefore holographic vacuum density is defined with standard gravitational constant in stead of the effective one. Dynamical and stability analysis shows four independent fixed points. One fixed point is stable and it corresponds to $w_{\text{eff}} = 1$. One branch of the stable fixedpoint solutions corresponds to deSitter expansion. The others are either unstable or saddle nodes. Numerical integration of the dynamical system are performed and plotted confronting with $H(z)$ data. It is found that for flat universe, $H(z)$ observational data favors large negative value of $\kappa$. Larger holographic contribution, $c$, and larger negative NMDC coupling increase slope and magnitude of the $w_{\text{eff}}$ and $H(z)$. Negative NMDC coupling can contribute to phantom equation of state, $w_{\text{eff}} < 1$. The NMDCspatial curvature coupling could also have phantom energy contribution. Moreover, free negative spatial curvature term can also contribute to phantom equation of state, but only with significantly large negative value of the spatial curvature.
 [2] arXiv:2402.18694 [pdf, ps, other]

Title: Smearing out contact terms in ghostfree infinite derivative quantum gravityComments: 6 pages, no figuresSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth)
In the context of ghostfree infinite derivative gravity we consider the single graviton exchange either between two spinless particles or between a spinless particle and a photon. To this end, we compute the gravitational potential for both cases and derive the quantum correction that arises at the linearized level. In the local theory it is wellknown that such a correction is in the form of a Dirac delta function. Here we show that, for the nonlocal theory and in contrast to the local theory, the quantum correction is smeared out and takes on nonzero values for a nonzero separation between the two particles.
 [3] arXiv:2402.18750 [pdf, ps, other]

Title: Wormholes supported by small extra dimensionsAuthors: Peter K.F. KuhfittigComments: 7 pages, no figuresJournalref: Adv. Studies Theor. Phys., vol. 18, no.1, pp. 4148, 2024Subjects: General Relativity and Quantum Cosmology (grqc)
Holding a MorrisThorne wormhole open requires a violation of the null energy condition, calling for the need for socalled exotic matter near the throat. Many researchers consider exotic matter to be completely unphysical in classical general relativity. It has been shown, however, that the existence of an extra macroscopic dimension can resolve this issue: the throat could be lined with ordinary matter, while the extra dimension is then responsible for the unavoidable energy violation. The purpose of this paper is to show that the extra dimension can be microscopic, a result that is consistent with string theory.
 [4] arXiv:2402.18785 [pdf, ps, other]

Title: On the semiclassical bounce with strong minimal assumptionsComments: 13 pages, 3 figuresSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth)
We explore the possibility of avoiding cosmological singularity with a bounce solution in the early Universe. The main finding is that simple and wellknown semiclassical correction, which describes the mixing of radiation and gravity in the effective action, may provide an analytic solution with a bounce. The solution requires a positive beta function for the total radiation term and the contraction of the Universe at the initial instant. The numerical estimate shows that the bounce may occur in an acceptable range of energies, but only under strong assumptions about the particle physics beyond the Standard Model.
 [5] arXiv:2402.18791 [pdf, other]

Title: Topological interpretation of extremal and Daviestype phase transitions of black holesComments: 17 pages, Two figuresSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth)
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, Daviestype phase transition, extremal phase transition, and HawkingPage (HP) transition. So far, the topological interpretation, where the critical point has been identified with the nonzero 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: Daviestype 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.} nonzero topological charge arising from different thermodynamic potentials in different types of phase transition.
 [6] arXiv:2402.18882 [pdf, other]

Title: Exploring the evolution of structure growth in the universe with fieldfluid interactions through dynamical stability analysisComments: 23 pages, 2 tables and 6 figuresSubjects: General Relativity and Quantum Cosmology (grqc)
We investigate an interacting quintessence dark energy  dark matter scenario and its impact on structure formation by analyzing the evolution of scalar perturbations. The interaction is introduced by incorporating a nonzero source term into the continuity equations of the two sectors (with opposite signs), modeled as $\bar{Q}_0 \equiv \alpha\bar{\rho}_{\rm m}(H + \kappa\dot{\phi})$. The coupling parameter $\alpha$ and the parameter $\lambda$ involved in quintessence potential $V(\phi) = V_0e^{\lambda\kappa\phi}$, play crucial roles in governing the dynamics of evolution examined within the present framework. The cosmic evolution, within this context, is depicted as a firstorder autonomous system of equations involving appropriately chosen dynamical variables. We analyzed the associated stability characteristics and growth rate of perturbations and obtained domains in the ($\alpha\lambda$) parameter space for which fixed points can exhibit stable and nonphantom accelerating solutions. Depending on its magnitude, the coupling parameter $\alpha$ has the potential to change the characteristics of certain critical points, altering them from attractors to repellers. This model effectively captures the evolutionary features of the universe across its various phases at both the background and perturbation levels. The issue of cosmic coincidence can also be addressed within the framework of this model. We also observed that for a moderate strength of coupling, the growth rate of matter perturbation extends into the distant future.
 [7] arXiv:2402.18915 [pdf, other]

Title: Observational constrained Weyl type $f(Q,T)$ gravity cosmological model and the dynamical system analysisComments: 17 pages, 7 figures, 4 tables. Suggestions and comments are welcomeSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth)
Using the cosmological date sets, the cosmological parameters are constrained in this paper, with some well known form of Hubble parameter. To understand the dynamics of the Weyl type $f(Q,T)$, functional form $f(Q,T)$ has been introduced, where $Q$ and $T$ respectively represents the nonmetricity scalar and trace of energymomentum tensor. Using the constrained values of the parameters, the other geometrical parameters are analysed and the accelerating behaviour has been shown. Further to get the complete evolutionary behaviour of the Universe, the dynamical system analysis has been performed.
 [8] arXiv:2402.18993 [pdf, ps, other]

Title: Kodamalike Vector Fields in Axisymmetric SpacetimesComments: 23 pages, 1 figure. Comments are welcomeSubjects: General Relativity and Quantum Cosmology (grqc)
We extend the concept of the Kodama symmetry, a quasilocal time translation symmetry for dynamical spherically symmetric spacetimes, to a specific class of dynamical axisymmetric spacetimes, namely the families of KerrVaidya and KerrVaidyade Sitter spacetimes. We study some geometrical properties of the asymptotically flat KerrVaidya metric, such as the BrownYork and ArnowittDeserMisner (ADM) masses, and the Einstein tensor. Furthermore, we propose a generalization of the KerrVaidya metric to an asymptotic de Sitter background. We show that for these classes of dynamical axisymmetric black hole spacetimes, there exists a timelike vector field that exhibits similar properties to the Kodama vector field in spherical symmetry. This includes the construction of a covariantly conserved current and a corresponding locally conserved charge, which in the asymptotically flat case coincides with the ADM mass at spatial infinity.
 [9] arXiv:2402.18997 [pdf, other]

Title: Motion of test particles in quasi antide Sitter regular black holesComments: 14 pages, 2 figures. Effort prepared for the Special Issue "20th Anniversary of IJGMMP"Subjects: General Relativity and Quantum Cosmology (grqc); Mathematical Physics (mathph)
We explore the characteristics of two novel regular spacetimes that exhibit a nonzero vacuum energy term, under the form of a (quasi) antide Sitter phase. Specifically, the first metric is spherical, while the second, derived by applying the generalized NewmanJanis algorithm to the first, is axisymmetric. We show that the equations of state of the effective fluids associated with the two metrics asymptotically tend to negative values, resembling quintessence. In addition, we study test particle motions, illustrating the main discrepancies among our models and more conventional metrics exhibiting nonvanishing antide Sitter phase.
 [10] arXiv:2402.19010 [pdf, ps, other]

Title: Reparametrization invariant action for Gravity with Dynamical Determinant of MetricAuthors: J. KlusonComments: 22 pagesSubjects: General Relativity and Quantum Cosmology (grqc)
We present manifestly reparametrization invariant action for theory of gravity with dynamical determinant of metric. We show that it is similar to a reparametrization invariant action for unimodular gravity. We determine canonical form of the action and study structure of constraints.
 [11] arXiv:2402.19051 [pdf, ps, other]

Title: The de Sitter swampland conjectures in the context of Chaplygininspired inflationComments: 8 pagesSubjects: General Relativity and Quantum Cosmology (grqc)
In this work, we discuss the de Sitter swampland conjectures in the context of the generalized Chaplygininspired inflationary model. We demonstrate that these conjectures can be satisfied, but only in the region of the parameter space far away from the General Relativity limit. The cosmic microwave background data had already been found to restrict the allowed inflationary potentials of this model. Our results impose a further limitation on the possible potentials.
 [12] arXiv:2402.19140 [pdf, other]

Title: Globally hyperbolic evaporating black hole and the information loss issueComments: 9 pages, 7 figuresSubjects: General Relativity and Quantum Cosmology (grqc)
We discuss the loss of information in black holes in the context of a globally hyperbolic spacetime that maintains unchanged the whole semiclassical picture except for the ``last evaporation breath,'' which actually pertains to full quantum gravity. Although observers outside the black hole will not have access to information that enters the horizon, no information is lost in the sense it is carried over from one Cauchy surface to the next one (provided the evolution is unitary). In this token, the loss of information in black holes becomes as benign (or distressing, at the reader's discretion) as in the usual classical stellar collapse into a nonevaporating black hole.
 [13] arXiv:2402.19310 [pdf, ps, other]

Title: Some Remarks on WangYau QuasiLocal MassSubjects: General Relativity and Quantum Cosmology (grqc); Mathematical Physics (mathph)
We review WangYau quasilocal definitions along the line of gravitational Hamiltonian. This makes clear the connection and difference between WangYau definition and BrownYork or even global ADM definition. We make a brief comment on admissibility condition in WangYau quasilcoal mass. We extend the positivity proof for WangYau quasilocal energy to allow possible presence of strictly stable apparent horizons through establishing solvability of Dirac equation in certain 3manifolds that possess cylindrical ends, as in the case of Jang's graph blowing up at marginally outer trapped surfaces.
 [14] arXiv:2402.19313 [pdf, other]

Title: Calibrating gravitationalwave search algorithms with conformal predictionComments: 18 pages, 20 figuresSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Astrophysical Phenomena (astroph.HE); Instrumentation and Methods for Astrophysics (astroph.IM)
In astronomy, we frequently face the decision problem: does this data contain a signal? Typically, a statistical approach is used, which requires a threshold. The choice of threshold presents a common challenge in settings where signals and noise must be delineated, but their distributions overlap. Gravitationalwave astronomy, which has gone from the first discovery to catalogues of hundreds of events in less than a decade, presents a fascinating case study. For signals from colliding compact objects, the field has evolved from a frequentist to a Bayesian methodology. However, the issue of choosing a threshold and validating noise contamination in a catalogue persists. Confusion and debate often arise due to the misapplication of statistical concepts, the complicated nature of the detection statistics, and the inclusion of astrophysical background models. We introduce Conformal Prediction (CP), a framework developed in Machine Learning to provide distributionfree uncertainty quantification to point predictors. We show that CP can be viewed as an extension of the traditional statistical frameworks whereby thresholds are calibrated such that the uncertainty intervals are statistically rigorous and the error rate can be validated. Moreover, we discuss how CP offers a framework to optimally build a metapipeline combining the outputs from multiple independent searches. We introduce CP with a toy cosmicray detector, which captures the salient features of most astrophysical search problems and allows us to demonstrate the features of CP in a simple context. We then apply the approach to a recent gravitationalwave Mock Data Challenge using multiple search algorithms for compact binary coalescence signals in interferometric gravitationalwave data. Finally, we conclude with a discussion on the future potential of the method for gravitationalwave astronomy.
 [15] arXiv:2402.19362 [pdf, ps, other]

Title: Dark energy and dark matter configurations for wormholes and solitionic hierarchies of nonmetric Ricci flows and $F(R,T,Q,T_{m})$ gravityComments: latex23, 11pt, 37 pages, with table of content; published online by EPJCJournalref: Eur. Phys. J. C 84 (2024) 211Subjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO); Mathematical Physics (mathph)
We extend the anholonomic frame and connection deformation method, AFCDM, for constructing exact and parametric solutions in general relativity, GR, to geometric flow models and modified gravity theories, MGTs, with nontrivial torsion and nonmetricity fields. Following abstract geometric or variational methods, we can derive corresponding systems of nonmetric gravitational and matter field equations which consist of very sophisticated systems of coupled nonlinear PDEs. Using nonholonomic frames with dyadic spacetime splitting and applying the AFCDM, we prove that such systems of PDEs can be decoupled and integrated in general forms for generic offdiagonal metric structures and generalized affine connections. We generate new classes of quasistationary solutions (which do not depend on time like coordinates) and study the physical properties of some physically important examples. Such exact or parametric solutions are determined by nonmetric solitonic distributions and/or ellipsoidal deformations of wormhole hole configurations. It is not possible to describe the thermodynamic properties of such solutions in the framework of the BekensteinHawking paradigm because such metrics do not involve, in general, certain horizons, duality, or holographic configurations. Nevertheless, we can always elaborate on associated Grigori Perelman thermodynamic models elaborated for nonmetric geometric flows. In explicit form, applying the AFCDM, we construct and study the physical implications of new classes of traversable wormhole solutions describing solitonic deformation and dissipation of nonRiemannian geometric objects. Such models with nontrivial gravitational offdiagonal vacuum are important for elaborating models of dark energy and dark matter involving wormhole configurations and solitonictype structure formation.
 [16] arXiv:2402.19373 [pdf, other]

Title: Revisiting stringinspired runningvacuum models under the lens of light primordial black holesAuthors: Theodoros Papanikolaou, Charalampos Tzerefos, Spyros Basilakos, Emmanuel N. Saridakis, Nick E. MavromatosComments: 20 pages plus appendices (30 pages in total), 9 figuresSubjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO); High Energy Physics  Theory (hepth)
Light primordial black holes (PBHs) with masses $M_\mathrm{PBH}<10^9\mathrm{g}$ can interestingly dominate the Universe's energy budget and give rise to early matterdominated (eMD) eras before Big Bang Nucleosyntesis (BBN). During this eMD era, one is met with an abundant production of induced gravitational waves (GWs) serving as a portal to constrain the underlying theory of gravity. In this work, we study this type of induced GWs within the context of stringinspired runningvaccuum models (StRVMs), which, when expanded around de Sitter backgrounds, include logarithmic corrections of the spacetime curvature. In particular, we discuss in detail the effects of StRVMs on the source as well as on the propagation of these PBHinduced GWs. Remarkably, under the assumption that the logarithmic terms represent quantum gravity corrections in the PBH era, we show that GW overproduction can be avoided if one assumes a coefficient of these logarithmic corrections that is much larger than the square of the reduced Planck mass. The latter cannot characterise quantum gravity corrections, though, prompting the need for revision of the quantisation of StRVMs in different than de Sitter backgrounds, such as those characterising PBHdriven eMD eras. This non trivial result suggests the importance of light PBHs as probes of new physics.
 [17] arXiv:2402.19397 [pdf, other]

Title: Testing gravitational waveforms in full General RelativityAuthors: Fabio D'Ambrosio, Francesco Gozzini, Lavinia Heisenberg, Henri Inchauspé, David Maibach, Jann ZossoComments: 22 pages, 15 figures, Comments are welcomeSubjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO); High Energy Physics  Phenomenology (hepph); High Energy Physics  Theory (hepth)
We perform a comprehensive analysis of stateoftheart waveform models, focusing on their predictions concerning kick velocity and inferred gravitational wave memory. In our investigation we assess the accuracy of waveform models using energymomentum balance laws, which were derived in the framework of full, nonlinear General Relativity. The numerical accuracy assessment is performed for precessing as well as nonprecessing scenarios for models belonging to the \textit{EOB}, \textit{Phenom}, and \textit{Surrogate} families. We analyze the deviations of these models from each other and from Numerical Relativity waveforms. Our analysis reveals statistically significant deviations, which we trace back to inaccuracies in modelling subdominant modes and inherent systematic errors in the chosen models. We corroborate our findings through analytical considerations regarding the mixing of harmonic modes in the computed kick velocities and inferred memories.
 [18] arXiv:2402.19459 [pdf, other]

Title: Anomalous contribution to galactic rotation curves due to stochastic spacetimeSubjects: General Relativity and Quantum Cosmology (grqc); Astrophysics of Galaxies (astroph.GA); High Energy Physics  Theory (hepth)
We consider a proposed alternative to quantum gravity, in which the spacetime metric is treated as classical, even while matter fields remain quantum. Consistency of the theory necessarily requires that the metric evolve stochastically. Here, we show that this stochastic behaviour leads to a modification of general relativity at low accelerations.
In the low acceleration regime, the variance in the acceleration produced by the gravitational field is high in comparison to that produced by the Newtonian potential, and acts as an entropic force, causing a deviation from Einstein's theory of general relativity. We show that in this "diffusion regime", the entropic force acts from a gravitational point of view, as if it were a contribution to the matter distribution.
We compute how this modifies the expectation value of the metric via the path integral formalism, and find that an entropic force driven by a stochastic cosmological constant can explain galactic rotation curves without needing to evoke dark matter. We caution that a greater understanding of this effect is needed before conclusions can be drawn, most likely through numerical simulations, and provide a template for computing the deviation from general relativity which serves as an experimental signature of the Brownian motion of spacetime.  [19] arXiv:2402.19468 [pdf, other]

Title: Gravitational wave constraints on planetarymass primordial black holes using LIGO O3a dataAuthors: Andrew L. Miller, Nancy Aggarwal, Sébastien Clesse, Federico De Lillo, Surabhi Sachdev, Pia Astone, Cristiano Palomba, Ornella J. Piccinni, Lorenzo PieriniComments: 6 pages main body, 2 pages appendix  comments are welcome! Upper limit data on Zenodo: this https URLSubjects: General Relativity and Quantum Cosmology (grqc)
Gravitational waves from subsolar mass inspiraling compact objects would provide smokinggun evidence for primordial black holes (PBHs). We perform the first search for inspiraling planetarymass PBHs, both in equalmass or asymmetric mass ratio binaries, using data from the first half of the LIGOVirgoKAGRA third observing run. We do not find any significant candidates, but determine the maximum luminosity distance reachable with our search to be of $O(0.1100)$ kpc, and corresponding modelindependent upper limits on the merger rate densities to be $O(10^{3}10^{7})$ kpc$^{3}$yr$^{1}$ for systems with chirp masses $O(10^{4}10^{2})M_\odot$, respectively. Furthermore, we interpret these rate densities as arising from PBH binaries, and thereby constrain the fraction of dark matter that these objects could compose. For equalmass PBH binaries, we find $f_\text{PBH}<$ [1, 0.04] for $m_\text{PBH}\in [2\times 10^{3},10^{2}]M_\odot$, respectively. For asymmetric massratio binaries, where $m_1=2.5M_\odot$ and $m_2\ll m_1$, we constrain the mass function $f(m_2)<1$ for $m_2\in [1.5\times10^{5},2\times10^{4}]M_\odot$, assuming $f_\text{PBH}=0.1$ and $f(m_1)\sim 1$. Our results constitute the first gravitationalwave constraints on planetarymass PBHs in both equalmass and highly asymmetric massratio systems, provide a computationally efficient alternative to matched filtering in this mass regime, and complement microlensing experiments to probe the existence of these objects. The data necessary to produce the upper limit plots has also been released on Zenodo.
Crosslists for Fri, 1 Mar 24
 [20] arXiv:2402.16938 (crosslist from hepth) [pdf, other]

Title: Dualities Among Massive, Partially Massless and Shift Symmetric Fields on (A)dSAuthors: Kurt HinterbichlerComments: 70 pagesSubjects: High Energy Physics  Theory (hepth); General Relativity and Quantum Cosmology (grqc)
We catalog all the electromagneticlike dualities that exist between free dynamical bosonic fields of arbitrary symmetry type and mass on (anti) de Sitter space in all dimensions, including dualities among the partially massless and shift symmetric fields. This generalizes to all these field types the well known fact that a massless $p$form is dual to a massless $(Dp2)$form in $D$ spacetime dimensions. In the process, we describe the structure of the Weyl modules (the spaces of local operators linear in the fields and their derivative relations) for all the massive, partially massless and shift symmetric fields.
 [21] arXiv:2402.18601 (crosslist from physics.plasmph) [pdf, other]

Title: Analytic solutions for the linearized firstorder magnetohydrodynamics and implications for causality and stabilityComments: 31 pages, 2 figuresSubjects: Plasma Physics (physics.plasmph); High Energy Astrophysical Phenomena (astroph.HE); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Phenomenology (hepph); Nuclear Theory (nuclth)
We solve the firstorder relativistic magnetohydrodynamics (MHD) within the linearmode analysis performed near an equilibrium configuration in the fluid rest frame. We find two complete sets of analytic solutions for the four and two coupled modes with seven dissipative transport coefficients. The former set has been missing in the literature for a long time. Our method provides a simple and general algorithm for the solution search on an orderbyorder basis in the derivative expansion, and can be applied to general sets of hydrodynamic equations. We also find that the smallmomentum expansions of the solutions break down when the momentum direction is nearly perpendicular to an equilibrium magnetic field due to the presence of another small quantity, that is, a trigonometric function representing the anisotropy. We elaborate on the angle dependence of the solutions and provide alternative series representations that work near the right angle. Finally, we discuss the issues of causality and stability based on our analytic solutions and recent developments in the literature.
 [22] arXiv:2402.18637 (crosslist from hepth) [pdf, other]

Title: Infrared finite scattering theory: Amplitudes and soft theoremsComments: 40 pages + appendicesSubjects: High Energy Physics  Theory (hepth); General Relativity and Quantum Cosmology (grqc); Mathematical Physics (mathph)
Any nontrivial scattering with massless fields in four spacetime dimensions will generically produce an outstate with memory. Scattering with any massless fields violates the standard assumption of asymptotic completeness  that all "in" and "out" states lie in the standard (zero memory) Fock space  and therefore leads to infrared divergences in the standard $S$matrix amplitudes. We define an infrared finite scattering theory valid for general quantum field theories and quantum gravity. The (infrared finite) "superscattering" map $\$$ is defined as a map between "in" and "out" states which does not require any a priori choice of a preferred Hilbert space. We define a "generalized asymptotic completeness" which accommodates states with memory in the space of asymptotic states. We define a complete basis of improper states on any memory Fock space (called "BMS particle" states) which are eigenstates of the energymomentum  or, more generally, the BMS supermomentum  that generalize the usual $n$particle momentum basis to account for states with memory. We then obtain infrared finite $\$$amplitudes defined as matrix elements of $\$$ in the BMS particle basis. This formulation of the scattering theory is a key step towards analyzing finegrained details of the infrared finite scattering theory. In quantum gravity, invariance of $\$$ under BMS supertranslations implies factorization of $\$$amplitudes as the frequency of one of the BMS particles vanishes. This proves an infrared finite analog of the soft graviton theorem. Similarly, an infrared finite soft photon theorem in QED follows from invariance of $\$$ under large gauge transformations. We comment on how one must generalize this framework to consider $\$$amplitudes for theories with collinear divergences (e.g., massless QED and YangMills theories).
 [23] arXiv:2402.18656 (crosslist from astroph.HE) [pdf, other]

Title: Primordial black holes or else? Tidal tests on subsolar mass gravitationalwave observationsComments: 15 pages, 15 figuresSubjects: High Energy Astrophysical Phenomena (astroph.HE); Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc)
The detection of a subsolar object in a compact binary merger is regarded as one of the smoking gun signatures of a population of primordial black holes (PBHs). We critically assess whether these systems could be distinguished from stellar binaries, for example composed of white dwarfs or neutron stars, which could also populate the subsolar mass range. At variance with PBHs, the gravitationalwave signal from stellar binaries is affected by tidal effects, which dramatically grow for moderately compact stars as those expected in the subsolar range. We forecast the capability of constraining tidal effects of putative subsolar neutron star binaries with current and future LIGOVirgoKAGRA (LVK) sensitivities as well as nextgeneration experiments. We show that, should LVK O4 run observe subsolar neutronstar mergers, it could measure the (large) tidal effects with high significance. In particular, for subsolar neutronstar binaries, O4 and O5 projected sensitivities would allow measuring the effect of tidal disruption on the waveform in a large portion of the parameter space, also constraining the tidal deformability at ${\cal O}(10\%)$ level, thus excluding a primordial origin of the binary. Viceversa, for subsolar PBH binaries, modelagnostic upper bounds on the tidal deformability can rule out neutron stars or more exotic competitors. Assuming events similar to the subthreshold candidate SSM200308 reported in LVK O3b data are PBH binaries, O4 projected sensitivity would allow ruling out the presence of neutronstar tidal effects at $\approx 3 \sigma$ C.L., thus strengthening the PBH hypothesis. Future experiments would lead to even stronger ($>5\sigma$) conclusions on potential discoveries of this kind.
 [24] arXiv:2402.18841 (crosslist from astroph.CO) [pdf, other]

Title: Perturbed $f(R)$ gravity coupled with neutrinos: exploring cosmological implicationsComments: 23 pages, 11 figuresSubjects: Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc)
We conduct a thorough examination of cosmological parameters within the context of $f(R)$ gravity coupled with neutrinos, leveraging a diverse array of observational datasets, including Cosmic Microwave Background (CMB), Cosmic Chronometers (CC), Baryon Acoustic Oscillations (BAO), and Pantheon supernova data. Our analysis unveils compelling constraints on pivotal parameters such as the sum of neutrino masses ($\sum m_{\nu}$), the interaction strength parameter ($\Gamma$), sound speed ($c_s$), Jean's wavenumbers ($k_J$), redshift of nonrelativistic matter ($z_{\rm nr}$), and the redshift of the DecelerationAcceleration phase transition ($z_{\rm DA}$). The incorporation of neutrinos within the $f(R)$ gravity framework emerges as a key factor significantly influencing cosmic evolution, intricately shaping the formation of largescale structures and the dynamics of cosmic expansion. Additionally, a detailed analysis of bulk flow direction and amplitude across various redshifts provides valuable insights into the nature of largescale structures. A notable aspect of our model is the nuanced integration of $f(R)$ gravity theory with neutrinos, representing a distinctive approach to unraveling cosmological phenomena. This framework, unlike previous models, explicitly considers the impact of neutrinos on gravitational interactions, the formation of largescale structures, and the overarching dynamics of cosmic expansion within the $f(R)$ gravity paradigm. Furthermore, our study addresses the Hubble tension problem by comparing $H_0$ measurements within our model, offering a potential avenue for reconciling discrepancies. Our findings not only align with existing research but also contribute novel perspectives to our understanding of dark energy, gravitational interactions, and the intricate challenges posed by the Hubble tension.
 [25] arXiv:2402.18894 (crosslist from astroph.HE) [pdf, other]

Title: Searches for beyondstandardmodel physics with astroparticle physics instrumentsJournalref: Phil. Trans. R. Soc. A. 382:230082, 05 February 2024, Volume 382, Issue 2266 230082Subjects: High Energy Astrophysical Phenomena (astroph.HE); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Experiment (hepex)
Many instruments for astroparticle physics are primarily geared towards multimessenger astrophysics, to study the origin of cosmic rays (CR) and to understand highenergy astrophysical processes. Since these instruments observe the Universe at extreme energies and in kinematic ranges not accessible at accelerators these experiments provide also unique and complementary opportunities to search for particles and physics beyond the standard model of particle physics. In particular, the reach of IceCube, Fermi and KATRIN to search for and constrain Dark Matter, Axions, heavy Big Bang relics, sterile neutrinos and Lorentz Invariance Violation (LIV) will be discussed. The contents of this article are based on material presented at the HumboldtKolleg "Clues to a mysterious Universe  exploring the interface of particle, gravity and quantum physics" in June 2022.
 [26] arXiv:2402.18965 (crosslist from astroph.CO) [pdf, other]

Title: Induced Gravitational Wave interpretation of PTA data: a complete study for general equation of stateComments: 22 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Phenomenology (hepph); High Energy Physics  Theory (hepth)
We thoroughly study the induced gravitational wave interpretation of the possible gravitational wave background reported by PTA collaborations, considering the unknown equation of state $w$ of the early universe. We perform a Bayesian analysis of the NANOGrav data using the publicly available \textsc{PTArcade} code together with \textsc{SIGWfast} for the numerical integration of the induced gravitational wave spectrum. We focus on two cases: a monochromatic and a lognormal primordial spectrum of fluctuations. For the lognormal spectrum, we show that, while the results are not very sensitive to $w$ when the GW peak is close to the PTA window, radiation domination is out of the $2\sigma$ contours when only the infrared powerlaw tail contributes. For the monochromatic spectrum, the $2\sigma$ bounds yield $0.1\lesssim w\lesssim0.9$ so that radiation domination is close to the central value. We also investigate the primordial black hole (PBH) counterpart using the peak formalism. We show that, in general terms, a larger width and stiffer equation of state alleviates the overproduction of PBHs. No PBH overproduction requires $w\gtrsim0.42$ up to 2$\sigma$ level for the monochromatic spectrum. Furthermore, including bounds from the cosmic microwave background, we find in general that the mass range of the PBH counterpart is bounded by $10^{5} M_\odot\lesssim M_{\rm PBH}\lesssim10^{1} M_\odot$. Lastly, we find that the PTA signal can explain the microlensing events reported by OGLE for $0.42\lesssim w\lesssim 0.50$. Our work showcases a complete treatment of induced gravitational waves and primordial black holes for general $w$ for future data analysis.
 [27] arXiv:2402.18967 (crosslist from astroph.CO) [pdf, other]

Title: Cosmological transition epoch from gammaray burst correlationsComments: 20 pages, 9 figures, 4 tablesSubjects: Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc)
The redshift $z_t$ and the jerk parameter $j_t$ of the transition epoch are constrained by using two modelindependent approaches involving the direct expansion of the Hubble rate and the expansion of the deceleration parameter around $z=z_t$. To extend our analysis to highredshifts, we employ the \emph{Amati}, \emph{Combo}, \emph{Yonetoku} and \emph{Dainotti} gammaray burst correlations. The \textit{circularity problem} is prevented by calibrating these correlations through the B\'ezier interpolation of the updated observational Hubble data. Each gammaray burst data set is jointly fit with type Ia supernovae and baryonic acoustic oscillations through a Monte Carlo analysis, based on the MetropolisHastings algorithm, to obtain $z_t$, $j_t$ and the correlation parameters. The overall results are compatible with the concordance model with some exceptions. We also focus on the behaviors of the dark energy, verifying its compatibility with a cosmological constant, and the matter density $\Omega_m$ and compare them with the expectations of the concordance paradigm.
 [28] arXiv:2402.19343 (crosslist from nuclth) [pdf, other]

Title: Infinite Order Hydrodynamics: an Analytical ExampleAuthors: Lorenzo GavassinoComments: 7 pages, two captioned figures, comments welcome!Subjects: Nuclear Theory (nuclth); High Energy Astrophysical Phenomena (astroph.HE); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Phenomenology (hepph); High Energy Physics  Theory (hepth)
We construct a kinetic model for matterradiation interactions where the hydrodynamic gradient expansion can be computed analytically up to infinite order in derivatives, in the fully nonlinear regime, and for arbitrary flows. The frequency dependence of the opacity of matter is chosen to mimic the relaxation time of a selfinteracting scalar field. In this way, the transient sector simulates that of a realistic quantum field theory. As expected, the gradient series is divergent for most flows. We identify the mechanism at the origin of the divergence, and we provide a successful regularization scheme. Additionally, we propose a universal qualitative framework for predicting the breakdown of the gradient expansion of an arbitrary microscopic system undergoing a given flow. This framework correctly predicts the factorial divergence of the gradient expansion in most nonlinear flows and its breakdown due to stochastic fluctuations. It also predicts that jets may induce an ultraviolet divergence in the gradient expansion of quark matter hydrodynamics.
Replacements for Fri, 1 Mar 24
 [29] arXiv:2305.06719 (replaced) [pdf, other]

Title: Geodesically complete cyclic cosmologies and entropyComments: 18 pages, 2 figures, the major revision has been done and some dubious analysis with entropy free models have been omitted, also the article in this form has been accepted in EPJCSubjects: General Relativity and Quantum Cosmology (grqc)
 [30] arXiv:2305.17582 (replaced) [pdf, ps, other]

Title: Electroweak symmetry breaking by gravityAuthors: Yuri ShtanovComments: 10 pages, one paragraph added, equation (2.20) corrected, matches the published versionJournalref: JHEP 02 (2024) 221Subjects: High Energy Physics  Phenomenology (hepph); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth)
 [31] arXiv:2306.03125 (replaced) [pdf, other]

Title: Symmetries and Selection Rules: Optimising Axion Haloscopes for Gravitational Wave SearchesComments: 28+22 pages, 3+2 figures; updated to match published versionSubjects: High Energy Physics  Phenomenology (hepph); Cosmology and Nongalactic Astrophysics (astroph.CO); Instrumentation and Methods for Astrophysics (astroph.IM); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Experiment (hepex)
 [32] arXiv:2306.11694 (replaced) [pdf, ps, other]

Title: Generalized second law of thermodynamics in massive gravityComments: 23 pages, 5 figuresJournalref: Eur. Phys. J. C 84, 40 (2024)Subjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO)
 [33] arXiv:2309.03286 (replaced) [pdf, ps, other]

Title: On dataset tensions and signatures of new cosmological physicsComments: 5 pages, additional references and discussionSubjects: Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc)
 [34] arXiv:2309.14535 (replaced) [pdf, other]

Title: A relativistic quantum broadcast channelComments: 15 pages, 1 figure, Accepted for Publication in PRDSubjects: General Relativity and Quantum Cosmology (grqc); High Energy Physics  Theory (hepth); Quantum Physics (quantph)
 [35] arXiv:2310.01734 (replaced) [pdf, other]

Title: New models of $4D$ and Extra dimensional black holes without inner horizon and with an integrable singularitySubjects: General Relativity and Quantum Cosmology (grqc)
 [36] arXiv:2310.15879 (replaced) [pdf, other]

Title: Prospects for probing the interaction between dark energy and dark matter using gravitationalwave dark sirens with neutron star tidal deformationComments: 13 pages, 9 figures; published in ApJJournalref: ApJ 963 (2024) 52Subjects: Cosmology and Nongalactic Astrophysics (astroph.CO); General Relativity and Quantum Cosmology (grqc); High Energy Physics  Phenomenology (hepph)
 [37] arXiv:2311.18221 (replaced) [pdf, other]

Title: Determining the corecollapse supernova explosion mechanism with current and future gravitationalwave observatoriesAuthors: Jade Powell, Alberto Iess, Miquel LlorensMonteagudo, Martin Obergaulinger, Bernhard Müller, Alejandro TorresForné, Elena Cuoco, José A. FontComments: Accepted in Physical Review DSubjects: High Energy Astrophysical Phenomena (astroph.HE); General Relativity and Quantum Cosmology (grqc)
 [38] arXiv:2312.13803 (replaced) [pdf, ps, other]

Title: The Subtle Simplicity of Cosmological CorrelatorsComments: 58 pages. Ancillary file recursions.nb implementing the recursions for the integrands of section 3 of the paper. v2: updated version with the evaluation of the correlators of phi_. Various clarifications and References updatedSubjects: High Energy Physics  Theory (hepth); General Relativity and Quantum Cosmology (grqc)
 [39] arXiv:2401.09170 (replaced) [pdf, other]

Title: Splitting the spacetime: A systematic analysis of foliation dependence in cosmic averagingComments: 34 pages. Updated version with minor revisionsSubjects: General Relativity and Quantum Cosmology (grqc); Cosmology and Nongalactic Astrophysics (astroph.CO)
 [40] arXiv:2401.12912 (replaced) [pdf, other]

Title: Searches for Compact Binary Coalescence Events Using Neural Networks in LIGO/Virgo Third Observation PeriodComments: 14 pages, 7 figuresSubjects: General Relativity and Quantum Cosmology (grqc); Instrumentation and Methods for Astrophysics (astroph.IM)
 [41] arXiv:2402.18550 (replaced) [pdf, other]

Title: Deformed neutron starsSubjects: General Relativity and Quantum Cosmology (grqc)
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