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General Relativity and Quantum Cosmology

New submissions

[ total of 39 entries: 1-39 ]
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New submissions for Thu, 23 Nov 17

[1]  arXiv:1711.08026 [pdf, ps, other]
Title: Cosmic acceleration in asymptotically Ricci flat Universe
Comments: 12 pages, 18 figures in 9 panels
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We analyze the evolution of a Friedmann-Robertson-Walker spacetime within the framework of $f(R)$ metric gravity using an exponential model. We show that $f(R)$ gravity may lead to a vanishing effective cosmological constant in the far future (i.e. $R\rightarrow 0$) and yet produce a transient accelerated expansion at present time with a potentially viable cosmological history. This is in contrast with several $f(R)$ models which, while viable, produce in general a non-vanishing effective cosmological constant asymptotically in time ($R\rightarrow 4\Lambda_{\rm eff}$). We also show that relativistic {stars in asymptotically flat spacetimes can be supported within this framework without encountering any singularity, notably in the Ricci scalar $R$.

[2]  arXiv:1711.08100 [pdf, other]
Title: Hairy AdS black holes with a toroidal horizon
Comments: 15 pages, 1 figure. Accepted for publication in Physics Letters B
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

An exact hairy asymptotically locally AdS black hole solution with a flat horizon in the Einstein-nonlinear sigma model system in (3+1) dimensions is constructed. The ansatz for the nonlinear $SU(2)$ field is regular everywhere and depends explicitly on Killing coordinates, but in such a way that its energy-momentum tensor is compatible with a metric with Killing fields. The solution is characterized by a discrete parameter which has neither topological nor Noether charge associated with it and therefore represents a hair. A $U(1)$ gauge field interacting with Einstein gravity can also be included. The thermodynamics is analyzed. Interestingly, the hairy black hole is always thermodynamically favored with respect to the corresponding black hole with vanishing Pionic field.

[3]  arXiv:1711.08193 [pdf, other]
Title: Conformal Invariance and Warped 5-Dimensional Spacetimes
Comments: Premature version. 7 pictures. Comment welcome. To present at "X Black Holes Workshop", Aveiro, Dec. 2017
Subjects: General Relativity and Quantum Cosmology (gr-qc)

We show that the Einstein field equations for a five-dimensional warped spacetime, where only gravity can propagate into the bulk, determine the dynamical evolution of the warp factor of the four-dimensional brane spacetime. This can be explained as a holographic manifestation. The warped 5D model can be reformulated by considering the warp factor as a dilaton field conformally coupled to gravity and embedded in a smooth $M_4 \otimes R$ manifold. On the brane, where the U(1) scalar-gauge fields live, the dilaton field manifests itself as a warp factor which determines the evolution of the metric components and matter fields. We write the Lagrangian of the Einstein-scalar-gauge fields in a conformal invariant setting. However, as expected, the conformal invariance is broken by the appearance of a mass term and a quadratic term in the energy-momentum tensor of the scalar-gauge field arising from the extrinsic curvature terms in the projected Einstein tensor. These terms can be interpreted as a constraint in order to maintain conformal invariance.

[4]  arXiv:1711.08221 [pdf, other]
Title: Towards an exascale code for GRMHD on dynamical spacetimes
Authors: Sven Köppel
Comments: submitted to Proceedings of ASTRONUM-2017 -- the 12th International Conference on Numerical Modeling of Space Plasma Flows (Journal of Physics: Conference Series). 10 pages, 7 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc)

We present the first results on the construction of an exascale hyperbolic PDE engine (ExaHyPE), a code for the next generation of supercomputers with the objective to evolve dynamical spacetimes of black holes, neutron stars and binaries. We solve a novel first order formulation of Einstein field equations in the conformal and constraint damping Z4 formulation (CCZ4) coupled to ideal general relativistic magnetohydrodynamics (GRMHD), using divergence-cleaning. We adopt a novel communication-avoiding one-step ADER-DG scheme with an a-posteriori subcell finite volume limiter on adaptive spacetrees. Despite being only at its first stages, the code passes a number of tests in special and general relativity.

[5]  arXiv:1711.08234 [pdf, other]
Title: Low Energy Lorentz Violation in Polymer Quantization Revisited
Comments: 11 pages, 3 figures, to appear in PLB
Subjects: General Relativity and Quantum Cosmology (gr-qc)

In previous work, it had been shown that polymer quantized scalar field theory predicts that even an inertial observer can experience spontaneous excitations. This prediction was shown to hold at low energies. However, in these papers it was assumed that the polymer scale is constant. But it is possible to relax this condition and obtain a larger class of theories where the polymer scale is a function of momentum. Does the prediction of low energy Lorentz violation hold for all of these theories? In this paper we prove that it does. We also obtain the modified rates of radiation for some of these theories.

[6]  arXiv:1711.08256 [pdf, ps, other]
Title: Rotating black hole in Rastall theory
Comments: 20 pages, 7 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc)

We discuss spherically symmetric exact black hole solution in the context of Rastall theory, and in turn present rotating black hole solution which generalize the Kerr-Newman solution. Interestingly, for a given value of Rastall parameter $\lambda$, there exists a critical rotation parameter $a_E$ which corresponds to an extremal black hole with degenerate horizons. We calculate the thermodynamical quantities associated for the rotating black hole. The particle motion is also analysed and behaviour of effective potential is discussed.

[7]  arXiv:1711.08285 [pdf, ps, other]
Title: Scalar-tensor black holes in an expanding universe
Comments: 18 pages, to be submitted to Universe (MDPI)
Subjects: General Relativity and Quantum Cosmology (gr-qc)

In this review we focus our attention on scalar-tensor gravity models and their empirical verification in terms of black hole and wormhole physics. We focus on a black hole, embedded in an expanding universe, describing both cosmological and astrophysical scales. We show that in scalar-tensor gravity it is quite common that the local geometry is isolated from the cosmological expansion, so that it does not backreact on the black hole metric. We try to extract common features of scalar-tensor black holes in an expanding universe and point out the gaps that must be filled.

[8]  arXiv:1711.08292 [pdf, other]
Title: New black holes in $D=5$ minimal gauged supergravity: deformed boundaries and 'frozen' horizons
Comments: 5 pages, 4 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

A new class of black hole solutions of the five dimensional minimal gauged supergravity is presented. They are characterized by the mass, the electric charge, two equal magnitude angular momenta and the magnitude of the magnetic potential at infinity. These black holes possess a horizon of spherical topology; however, both the horizon and the sphere at infinity can be arbitrarily squashed, with nonextremal solutions interpolating between black strings and black branes. A particular set of extremal configurations corresponds to a new one-parameter family of supersymmetric black holes. While their conserved charges are determined by the squashing of the sphere at infinity, these supersymmetric solutions possess the same horizon geometry.

[9]  arXiv:1711.08298 [pdf, other]
Title: Black hole superradiance and polarization-dependent bending of light
Comments: Bulk of 29 pages + 11 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)

An inhomogeneous pseudo-scalar field configuration behaves like an optically active medium. Consequently, if a light ray passes through an axion cloud surrounding a Kerr black hole, it may experience a polarization-dependent bending. We explore the size and relevance of such effect considering both the QCD axion and a generic axion-like particle.

[10]  arXiv:1711.08329 [pdf, other]
Title: Statefinder diagnostic and constraints on the Palatini f(R) gravity theories
Comments: 19 pages, 10 figures, accepted by RAA (Res. Astron. Astrophys.) arXiv admin note: text overlap with arXiv:1002.3867
Subjects: General Relativity and Quantum Cosmology (gr-qc)

In this paper, we focus on a series of $f(R)$ gravity theories in Palatini formalism to investigate the probabilities of producing the late-time acceleration for the flat Friedmann-Robertson-Walker (FRW) universe. We apply statefinder diagnostic to these cosmological models for chosen series of parameters to see if they distinguish from one another. The diagnostic involves the statefinder pair $\{r,s\}$, where $r$ is derived from the scale factor $a$ and its higher derivatives with respect to the cosmic time $t$, and $s$ is expressed by $r$ and the deceleration parameter $q$. In conclusion, we find that although two types of $f(R)$ theories: (i) $f(R) = R + \alpha R^m - \beta R^{-n}$ and (ii) $f(R) = R + \alpha \ln R - \beta$ can lead to late-time acceleration, their evolutionary trajectories in the $r-s$ and $r-q$ planes reveal different evolutionary properties, which certainly justify the merits of statefinder diagnostic. Additionally, we utilize the observational Hubble parameter data (OHD) to constrain these models of $f(R)$ gravity. As a result, except for $m=n=1/2$ of (i) case, $\alpha=0$ of (i) case and (ii) case allow $\Lambda$CDM model to exist in 1$\sigma$ confidence region. After adopting statefinder diagnostic to the best-fit models, we find that all the best-fit models are capable of going through deceleration/acceleration transition stage with late-time acceleration epoch, and all these models turn to de-Sitter point ($\{r,s\}=\{1,0\}$) in the future. Also, the evolutionary differences between these models are distinct, especially in $r-s$ plane, which makes the statefinder diagnostic more reliable in discriminating cosmological models.

[11]  arXiv:1711.08334 [pdf, other]
Title: Closed timelike curves and the second law of thermodynamics
Comments: 6 pages, 3 figures, comments welcome
Subjects: General Relativity and Quantum Cosmology (gr-qc)

One out of many emerging implications from solutions of Einstein's general relativity equations are closed timelike curves (CTCs), which are trajectories through spacetime that loop back on themselves in the form of wormholes. Two main physical models of computation with the use of CTCs were introduced by Deutsch (D-CTC) and by Bennett and Schumacher (P-CTC). Both of the models operate on the two systems: chronology-respecting system and chronology-violating CTC system, which interact with one another through some unitary operation. In the first model, the self-consistency condition is imposed on the density matrix of the CTC system, which always provides a solution that do not lead to logical time-like paradoxes, whereas the P-CTC model chooses such solution through post-selection. Both models are non-equivalent and imply nonstandard phenomena in the field of quantum computation and quantum mechanics. In this work, we add a point to the long lasting discourse about which model is more accurate, and study the implications of the two models on the second law of thermodynamics, the fundamental principle which states that in the isolated system the entropy never decreases.

[12]  arXiv:1711.08372 [pdf, ps, other]
Title: Black branes and black strings in the astrophysical and cosmological context
Comments: 7 pages, no figures and tables
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

We consider Kaluza-Klein models where internal spaces are compact flat or curved Einstein spaces. This background is perturbed by a compact gravitating body with the dust-like equation of state (EoS) in the external/our space and an arbitrary EoS parameter $\Omega$ in the internal space. Without imposing any restrictions on the form of the perturbed metric and the distribution of the perturbed energy densities, we perform the general analysis of the Einstein and conservation equations in the weak-field limit. All conclusions follow from this analysis. For example, we demonstrate that the perturbed model is static and perturbed metric preserves the block-diagonal form. In a particular case $\Omega=-1/2$, the found solution corresponds to the weak-field limit of the black strings/branes. The black strings/branes are compact gravitating objects which have the topology (four-dimensional Schwarzschild spacetime)$\times$ ($d$-dimensional internal space) with $d\geq 1$. We present the arguments in favour of these objects. First, they satisfy the gravitational tests for the parameterized post-Newtonian parameter $\gamma$ at the same level of accuracy as General Relativity. Second, they are preferable from the thermodynamical point of view. Third, averaging over the Universe, they do not destroy the stabilization of the internal space. These are the astrophysical and cosmological aspects of the black strings/branes.

[13]  arXiv:1711.08380 [pdf, ps, other]
Title: Shadow cast by rotating braneworld black holes with a cosmological constant
Comments: 12 pages, 4 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc)

In this article, we study the shadow produced by rotating black holes with a tidal charge in a Randall-Sundrum braneworld model, with a cosmological constant. We obtain the apparent shape and the corresponding observables for different values of the tidal charge and the rotation parameter, and we analyze the influence of the presence of the cosmological constant. We also discuss the observational prospects for this optical effect.

[14]  arXiv:1711.08400 [pdf, ps, other]
Title: A regular scale-dependent black hole solution
Comments: Accepted in Int. J Mod.Phys. D
Subjects: General Relativity and Quantum Cosmology (gr-qc)

In this work, we present a regular black hole solution, in the context of scale-dependent General Relativity, satisfying the weak energy condition. The source of this solution is an anisotropic effective energy-momentum tensor which appears when the scale dependence of the theory is turned-on. In this sense, the solution can be considered as a semiclassical extension of the Schwarzschild one.

Cross-lists for Thu, 23 Nov 17

[15]  arXiv:1711.07903 (cross-list from hep-th) [pdf, other]
Title: Diffusion in higher dimensional SYK model with complex fermions
Subjects: High Energy Physics - Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); General Relativity and Quantum Cosmology (gr-qc)

We construct a new higher dimensional SYK model with complex fermions on bipartite lattices. As an extension of the original zero-dimensional SYK model, we focus on the one-dimension case, and similar Hamiltonian can be obtained in higher dimensions. This model has a conserved U(1) fermion number Q and a conjugate chemical potential \mu. We evaluate the thermal and charge diffusion constants via large q expansion at low temperature limit. The results show that the diffusivity depends on the ratio of free Majorana fermions to Majorana fermions with SYK interactions. The transport properties and the butterfly velocity are accordingly calculated at low temperature. The thermal conductivity is proportional to the temperature.

[16]  arXiv:1711.07984 (cross-list from astro-ph.CO) [pdf, other]
Title: Peering beyond the horizon with standard sirens and redshift drift
Authors: Raul Jimenez (1,2), Alvise Raccanelli (1), Licia Verde (1,2), Sabino Matarrese (3,4,5,6) ((1) ICC Barcelona, (2) ICREA, (3) Università di Padova, (4) INFN Padova, (5) INAF Padova, (6) GSSI)
Comments: 10 pages, 1 figure, 2 tables
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

An interesting test on the nature of the Universe is to measure the global spatial curvature of the metric in a model independent way, at a level of $|\Omega_k|<10^{-4}$, or, if possible, at the cosmic variance level of the amplitude of the CMB fluctuations $|\Omega_k|\approx10^{-5}$. A limit of $|\Omega_k|<10^{-4}$ would yield stringent tests on several models of inflation. Further, improving the constraint by an order of magnitude would help in reducing "model confusion" in standard parameter estimation. Moreover, if the curvature is measured to be at the value of the amplitude of the CMB fluctuations, it would offer a powerful test on the inflationary paradigm and would indicate that our Universe must be significantly larger than the current horizon. On the contrary, in the context of standard inflation, measuring a value above CMB fluctuations will lead us to conclude that the Universe is not much larger than the current observed horizon; this can also be interpreted as the presence of large fluctuations outside the horizon. However, it has proven difficult, so far, to find observables that can achieve such level of accuracy, and, most of all, be model-independent. Here we propose a method that can in principle achieve that; this is done by making minimal assumptions and using distance probes that are cosmology-independent: gravitational waves, redshift drift and cosmic chronometers. We discuss what kind of observations are needed in principle to achieve the desired accuracy.

[17]  arXiv:1711.08125 (cross-list from hep-th) [pdf, ps, other]
Title: Ghost-free theory with third-order time derivatives
Comments: 5 pages
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

As the first step to extend our understanding of higher-derivative theories, within the framework of analytic mechanics of interacting particles, we construct a ghost-free theory involving third-order time derivative in Lagrangian. We clarify that there is a crucial difference in construction from up-to-second-order-derivative theories. While eliminating linear momentum terms in the Hamiltonian is necessary and sufficient to kill the ghosts associated with the higher derivatives for the Lagrangian with up to second-order derivatives, this is necessary but not sufficient for the Lagrangian with higher than second-order derivatives. We demonstrate that even after eliminating the linear momentum terms ghosts are still lurking and they need to be removed appropriately to make Lagrangian free from the ghosts. We clarify a set of ghost-free conditions under which we show that the Hamiltonian is bounded, and that equations of motion are reducible into a second-order system.

[18]  arXiv:1711.08312 (cross-list from hep-th) [pdf, ps, other]
Title: Weak gravitation from a small extra 2D sphere
Comments: 16 pages, no figures
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)

In order to explain weak gravitation in our 4-dimensional universe, a 6-dimensional model with a small extra 2D sphere is proposed. The traceless energy-momentum tensor is quite naturally appeared in our 6-dimensional model. The warp factor is given by $\phi (\theta ) = \epsilon + \sin{\theta }$, where $\epsilon $ plays a role of killing the singular point $\phi (\theta )=0$, and is assumed $0 < \epsilon \ll 1$. Any massive particle is rolling down into points along this geodesic line. The light ray can be shown to stay in our 4-dimensional universe. This suggest us that our 4-dimensional world can be located at $\theta =0 $ and/or $\theta = \pi $, its background metric being $\epsilon ^2 \eta _{\mu \nu }$. As a result, we have the 4-dimensional Newton constant, which is given by $G_N \simeq G_6 \epsilon ^{10}$ and the fifth force coefficients appeared here are $\alpha _i\simeq \epsilon ^{2(i-4)}$, $i=1, 2, 3$. Here $G_6$ is the gravitational constant in 6-dimensional spacetime. If we take $\epsilon = 10^{-3.8}$ against $G_6\sim 1($GeV$)^{-2}$, we get $G_N\sim 10^{-38}($Gev$)^{-2}$, the present time gravitational constant.

[19]  arXiv:1711.08315 (cross-list from hep-th) [pdf, ps, other]
Title: On the propagation of gravitational waves in a $Λ$CDM universe
Comments: 18 pages, 2 figures
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)

We study here how the presence of non-zero matter density and a cosmological constant could affect the observation of gravitational waves in Pulsar Timing Arrays. Conventionally, the effect of matter and cosmological constant is included by considering the redshift in frequency due to the expansion. However, there is an additional effect due to the change of coordinate systems from the natural ones in the region where waves are produced to the ones used to measure the pulsar timing residuals. This change is unavoidable as the strong gravitational field in a black hole merger distorts clocks and rules. Harmonic waves produced in such a merger become anharmonic when detected by a cosmological observer. The effect is small but appears to be observable for the type of gravitational waves to which PTA are sensitive and for the favoured values of the cosmological parameters.

[20]  arXiv:1711.08370 (cross-list from hep-th) [pdf, other]
Title: Fluctuations through a Vibrating Bounce
Comments: 17 pages, 5 figures
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We study the evolution of cosmological perturbations in a non-singular bouncing cosmology with a bounce phase which has superimposed oscillations of the scale factor. We identify length scales for which the final spectrum of fluctuations obtains imprints of the non-trivial bounce dynamics. These imprints in the spectrum are manifested in the form of damped oscillation features at scales smaller than a characteristic value and an increased reddening of the spectrum at all the scales as the number of small bounces increases.

[21]  arXiv:1711.08386 (cross-list from astro-ph.HE) [pdf, ps, other]
Title: Reduced Order Modelling in searches for continuous gravitational waves - I. barycentering time delays
Comments: 11 pages, 8 figures
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

The frequencies and phases of emission from extra-solar sources, as measured by Earth-bound observers, are modulated due to the Doppler motions of the observer with respect to the source, and through relativistic effects. These modulations depend critically on the sky-location of the source. Precise knowledge of the modulations is required if wanting to coherently track the phase of a source over long observation times, for example in pulsar timing, or searches for continuous gravitational wave sources. The modulations can be modelled as a sky-location and time dependent time delay that converts arrival times at the observer to the inertial frame of the source. In many cases this inertial frame can be the solar system barycentre (SSB). We study the use of Reduced Order Modelling for speeding up the calculation of the time delay between an observer and the SSB for any sky-location and for coherent observations spanning one year. We find that the time delay model can be decomposed into just four basis vectors, which can be used to reconstruct the time delay for any sky-location to sub-nanosecond accuracy. When compared to the standard routines for time delay calculation used in gravitational wave searches, the use of the reduced basis can lead to a speed-up factor of 30 times. We have also studied the components of equivalent time delays for sources in binary systems. For these, assuming eccentricities less than 0.25, we can reconstruct the delays to within 100s of nanoseconds, with best case speed-ups of a factor of 10, or factors of two when having to interpolate the basis to different orbital periods or time stamps. In long-duration phase-coherent searches for sources with large sky-position uncertainties, or binary parameter uncertainties, these speed-ups could allow enhancements in their scopes without large additional computational burdens.

[22]  arXiv:1711.08403 (cross-list from hep-th) [pdf, ps, other]
Title: Spacetime from locality of interactions in deformations of special relativity: the example of $κ$-Poincaré Hopf algebra
Comments: 14 pages
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)

A new proposal for the notion of spacetime in a relativistic generalization of special relativity based on a modification of the composition law of momenta is presented. Locality of interactions is the principle which defines the spacetime structure for a system of particles. The formulation based on $\kappa$-Poincar\'e Hopf algebra is shown to be contained in this framework as a particular example.

[23]  arXiv:1711.08441 (cross-list from astro-ph.CO) [pdf, other]
Title: Reconstruction of a direction-dependent primordial power spectrum from Planck CMB data
Comments: 32 pages, 22 figures, 6 tables
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

We consider the possibility that the primordial curvature perturbation is direction-dependent. To first order this is parameterised by a quadrupolar modulation of the power spectrum and results in statistical anisotropy of the cosmic microwave background, which can be quantified using the bipolar spherical harmonic representation. We compute these for the Planck Release 2 SMICA map and use them to infer the quadrupole modulation of the primordial power spectrum which, going beyond previous work, we allow to be scale-dependent. Uncertainties are estimated from Planck FFP9 simulations. Consistent with the Planck collaboration's findings, we find no evidence for a constant quadrupole modulation, nor one scaling with wave number as a power law. However our non-parametric reconstruction suggests several spectral features. When a constant quadrupole modulation is fitted to data limited to the wave number range $0.005 \leq k/\mathrm{Mpc}^{-1} \leq 0.008$, we find that its preferred direction is aligned with the cosmic hemispherical asymmetry. To determine the statistical significance we construct two different test statistics and test them on our reconstructions from data, against reconstructions of realisations of noise only. With a test statistic sensitive only to the amplitude of the modulation, the reconstructions are unusual at $2.5\sigma$ significance in the full wave number range, but at $2.2\sigma$ when limited to the intermediate wave number range $0.008 \leq k/\mathrm{Mpc}^{-1} \leq 0.074$. With the second test statistic, sensitive also to direction, the reconstructions are unusual with $4.6\sigma$ significance, dropping to $2.7 \sigma$ for the intermediate wave number range. Our approach is easily generalised to include other data sets such as polarisation, large-scale structure and forthcoming 21-cm line observations which will enable these anomalies to be investigated further.

Replacements for Thu, 23 Nov 17

[24]  arXiv:1503.05878 (replaced) [pdf, ps, other]
Title: Inhomogeneous cosmology in the cosmic rest frame revisited
Authors: Günter Scharf
Comments: 21 pages, no figure
Subjects: General Physics (physics.gen-ph); General Relativity and Quantum Cosmology (gr-qc)
[25]  arXiv:1510.06655 (replaced) [pdf, ps, other]
Title: On the Global Casimir Effect in the Schwarzschild Spacetime
Comments: New version with 15 pages and 3 figures. To appear in JCAP
Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[26]  arXiv:1607.02094 (replaced) [pdf, other]
Title: Magneto-optic effects of the Cosmic Microwave Background
Authors: Damian Ejlli
Comments: Additional references added. More details have been added in the introduction and discussion sections. Slightly reduced version with respect to previous one. Unchanged final results
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
[27]  arXiv:1607.05123 (replaced) [pdf, ps, other]
Title: Imprint of thawing scalar fields on large scale galaxy overdensity
Comments: Revised version with new results, comments welcome
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
[28]  arXiv:1701.01046 (replaced) [pdf, ps, other]
Title: Gravastars with higher dimensional spacetimes
Comments: 14 pages, 5 figures with considerable changes in the text
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[29]  arXiv:1703.08886 (replaced) [pdf, ps, other]
Title: Constant scalar curvature hypersurfaces in $(3+1)$-dimensional GHMC Minkowski spacetimes
Authors: Graham Smith
Subjects: Differential Geometry (math.DG); General Relativity and Quantum Cosmology (gr-qc)
[30]  arXiv:1706.07011 (replaced) [pdf, other]
Title: Frame Covariant Nonminimal Multifield Inflation
Comments: 43 pages, 12 figures; typos corrected; references added; revised version resubmitted to journal
Subjects: High Energy Physics - Phenomenology (hep-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
[31]  arXiv:1707.06827 (replaced) [pdf, other]
Title: Constraining interacting dark energy with CMB and BAO future surveys
Comments: 15 pages, 10 figures. Replaced to match published version
Journal-ref: Phys. Rev. D 96, 103529 (2017)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
[32]  arXiv:1708.03554 (replaced) [pdf, ps, other]
Title: Massive gravitons in arbitrary spacetimes
Comments: 7 pages, presentation is more detailed, Appendix expanded, eq.(12) corrected, references added
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)
[33]  arXiv:1709.03420 (replaced) [pdf, other]
Title: Clustering dark energy and halo abundances
Comments: 18 pages and 9 figures, v2: references added and some points clarified, matches the accepted version in JCAP
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
[34]  arXiv:1710.07252 (replaced) [pdf, other]
Title: Conserved Charges in Extended Theories of Gravity
Comments: 114 pages, 1 figure, a review, references added
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)
[35]  arXiv:1711.00584 (replaced) [pdf, other]
Title: Optical drift effects in general relativity
Comments: 38 pages, 9 figures. Added new references, corrected typos, expanded Sec. 3.3, 4.2, corrected equations in Sec. 3.5 and Appendix
Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
[36]  arXiv:1711.02330 (replaced) [pdf, other]
Title: A bare quantum null energy condition
Comments: 4 pages, no figure; v2: minor corrections
Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)
[37]  arXiv:1711.03737 (replaced) [pdf, ps, other]
Title: Soft Theorems For Shift-Symmetric Cosmologies
Comments: 4 pages; citation added in v2
Subjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)
[38]  arXiv:1711.05212 (replaced) [pdf, other]
Title: Radiation-Reaction Force on a Small Charged Body to Second Order
Comments: 31 pages, 2 figures
Subjects: General Relativity and Quantum Cosmology (gr-qc)
[39]  arXiv:1711.06811 (replaced) [pdf, ps, other]
Title: Exact solution of the wave equation of a scalar particle in the zero mass limit of Kerr and Kerr-(anti-)de-Sitter space-times
Comments: 6 pages. Some typos are corrected
Subjects: General Relativity and Quantum Cosmology (gr-qc); Mathematical Physics (math-ph)
[ total of 39 entries: 1-39 ]
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