Dynamically Generated Inflationary Lambda-CDM

**scalar**

**field**with a non-trivial inflationary potential and with an additional interaction with the dynamically generated dark matter. Expand abstract.

**scalar**

**field**employing the formalism of non-Riemannian spacetime volume-elements. The non-Riemannian volume element in the initial

**scalar**

**field**action leads to a hidden nonlinear Noether symmetry which produces energy-momentum tensor identified as a sum of a dynamically generated cosmological constant and a dust-like dark matter. The non-Riemannian volume-element in the initial Einstein-Hilbert action upon passage to the physical Einstein-frame creates dynamically a second

**scalar**

**field**with a non-trivial inflationary potential and with an additional interaction with the dynamically generated dark matter. The resulting Einstein-frame action describes a fully dynamically generated inflationary model coupled to dark matter. Numerical results for observables such as the

**scalar**power spectral index and the tensor-to-

**scalar**ratio conform to the latest 2018 PLANCK data.

7/10 relevant

Preprints.org

Distinguishing Brans-Dicke-Kerr type naked singularities and black holes with their thin disk electromagnetic radiation properties

**scalar**

**field**. The solution of the

**field**equations contains the Kerr metric as a particular case, and, depending on the numerical values of the model parameter $\gamma$, has also solutions corresponding to non-trivial black holes and naked singularities, respectively. Due to the differences in the exterior geometries between black holes and Brans-Dicke-Kerr naked singularities, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution and equilibrium radiation spectrum) are different for these two classes of compact objects, consequently giving clear observational signatures that could discriminate between black holes and naked singularities.

4/10 relevant

arXiv

A Neutron Star with a Strange Quark Star-like Mass-Radius Relation

**scalar**

**field**having a potential of the form $V(\phi)=-\mu^2\phi^2/2+\lambda\phi^4/4$. We numerically solve equations of the system using two different realistic equations of state for neutron matter and give the mass-radius relations as well as the radial profiles of the

**scalar**field, densities and the mass function for a sample configuration. We show that a specific solution type encountered in such systems causes characteristic neutron star mass-radius relations to turn into the ones belonging to strange quark stars.

5/10 relevant

arXiv

Second moment fuzzy-field-theory-like matrix models

**scalar**

**field**theory on the fuzzy sphere and obtain its phase diagram. Expand abstract.

**scalar**

**field**theory on the fuzzy sphere and obtain its phase diagram. We generalize this method to models with modified kinetic terms and demonstrate its use by investigating models related to the removal of the UV/IR mixing. We show that for the fuzzy sphere a modification of the kinetic part of the action by higher derivative term can change the phase diagram of the theory such that the triple point moves further from the origin.

4/10 relevant

arXiv

Conformal structure of FLRW Cosmology: Spinorial representation and the so(3,2) algebra of observables

**scalar**

**field**coupled to general relativity exhibits a new hidden conformal invariance under Mobius transformation of the proper time, additionally to the invariance under time-reparamterization. The resulting Noether charges form a $sl(2,\mathbb{R})$ Lie algebra, which encapsulates the whole kinematics and dynamics of the geometry. This allows to map FLRW cosmology onto conformal mechanics and formulate quantum cosmology in $\text{CFT}_1$ terms. Here, we show that this conformal structure is embedded in a larger $so(3,2)$ algebra of observables, which allows to present all the Dirac observables for the whole gravity plus matter sectors in a unified picture. Not only this allows one to quantize the system and its whole algebra of observables as a single irreducible representation of $so(3,2)$, but this also gives access to a

**scalar**

**field**operator $\hat{\phi}$ opening the door to the inclusion of non-trivial potentials for the

**scalar**

**field**. As such, this extended conformal structure might allow to perform a group quantization of inflationary cosmological backgrounds.

7/10 relevant

arXiv

Mass inflation and the $C^2$-inextendibility of spherically symmetric
charged **scalar** **field** dynamical black holes

**scalar**

**field**on the event horizon that - either mass inflation occurs on the entire Cauchy horizon emanating from time-like infinity $\mathcal{CH}_{i^+}$, - or $\mathcal{CH}_{i^+}$ is isometric to a Reissner-Nordstr\"{o}m Cauchy horizon i.e. the radiation is zero on the Cauchy horizon. In both cases, we prove that $\mathcal{CH}_{i^+}$ is globally $C^2$-inextendible. To this end, we establish a novel classification of Cauchy horizons into three types: dynamical, static or mixed. As a side benefit, we prove that there exists a trapped neighborhood of the Cauchy horizon, thus the apparent horizon cannot cross the Cauchy horizon, a result of independent interest. Our main motivation is to prove the $C^2$ Strong Cosmic Censorship Conjecture for a realistic model of spherical collapse in which charged matter emulates the repulsive role of angular momentum. In our case, this model is the Einstein-Maxwell-Klein-Gordon system on space-times with one asymptotically flat end. As a consequence of the $C^2$-inextendibility of the Cauchy horizon, we prove the following statements, in spherical symmetry: - two-ended asymptotically flat space-times are $C^2$-future-inextendible i.e. $C^2$ Strong Cosmic Censorship is true for Einstein-Maxwell-Klein-Gordon, assuming the decay of the

**scalar**

**field**on the event horizon at the expected rate. - In the one-ended case, under the same assumptions, the Cauchy horizon emanating from time-like infinity is $C^2$-inextendible. This result suppresses the main obstruction to $C^2$ Strong Cosmic Censorship in spherical collapse.

10/10 relevant

arXiv

Test the Weak Cosmic Censorship Conjecture in Torus-Like Black Hole
under Charged **Scalar** **Field**

**scalar**

**field**scattering we consider, in the extend phase space, the first law of thermodynamics and the weak cosmic censorship conjecture are valid. Expand abstract.

**scalar**

**field**scattering. Using the relation between the conserved quantities of a black hole and the

**scalar**field, we can calculate the change of the energy and charge within the infinitesimal time. The change of the enthalpy is connected to the change of energy, then we use those results to test whether the first law, the second law as well as the weak cosmic censorship conjecture are valid. In the normal phase space, the first law of thermodynamics and the weak cosmic censorship conjecture are valid, and the second law of thermodynamics is not violated. For the specific black hole under

**scalar**

**field**scattering we consider, in the extend phase space, the first law of thermodynamics and the weak cosmic censorship conjecture are valid. However, the second law of thermodynamics is violated when the black hole's initial charge reaches a certain value.

10/10 relevant

arXiv

Harrison-Zel'dovich **scal**e invariance and the exponential decrease of the
"cosmological constant" in the super-early Universe

**scalar**

**field**is introduced. Expand abstract.

**scalar**

**field**is introduced. The stage of a super-early (Harrison-Zel'dovich) scale invariant Universe is considered. It is shown that while the scale factor sharply increases and demonstrates inflationary behavior, the generalized cosmological constant decreases sharply from a huge value at the beginning of the Big Bang to an extremely small value in the modern era, which solves the well-known "cosmological constant problem".

4/10 relevant

arXiv

Real-time Dynamics of Plasma Balls

**scalar**

**field**collapse then produces an excited black hole at the bottom of the geometry together with gravitational and

**scal**ar radiation. Expand abstract.

**scalar**

**field**. Prompt

**scalar**

**field**collapse then produces an excited black hole at the bottom of the geometry together with gravitational and

**scalar**radiation. The radiation disperses to infinity in the non-compact directions and corresponds to particle production in the dual gauge theory. The black hole evolves towards the dual of an equilibrium plasma ball on a time scale longer than naively expected. This feature is a direct consequence of confinement and is caused by long-lived, periodic disturbances bouncing between the bottom of the AdS soliton and the AdS boundary.

4/10 relevant

arXiv

Quantum simulation of Unruh-DeWitt detectors with nonlinear optics

**scalar**field, with a suitably-engineered $\chi^{(2)}$ nonlinear interaction. In this simulation, the parameter playing the role of the detector acceleration is played by the relative inverse-group-velocity gradient inside the nonlinear material. We identify experimental parameters that tune the detector energy gap, acceleration, and switching function. This system can simulate time-dependent acceleration, time-dependent detector energy gaps, and non-vacuum initial detector-

**field**states. Furthermore, for very short materials, the system can simulate the weak anti-Unruh effect, in which the response of the detector decreases with acceleration. While some Unruh-related phenomena have been investigated in nonlinear optics, this is the first proposal for simulating an Unruh-DeWitt detector in these systems.

4/10 relevant

arXiv