Loop Quantum Cosmology (LQC), mainly due to Bojowald, is not the cosmological sector of Loop Quantum Gravity (LQG). Rather, LQC consists of a truncation of the phase space of classical General Relativity to spatially homogeneous situations which is then quantized by the methods of LQG. Thus, LQC is a quantum mechanical toy model (finite number of degrees of freedom) for LQG (a genuine QFT with ...

In this paper we study the dynamical contact angle at three phase (fluid-fluid-solid) contact points for the 2 dimensional steady-state moving liquid drop. We present a result giving the speeds at the contact points as a function of the dynamical contact angle, in the form of a simple algebraic expression. The only physical constants involved are the viscosities of the fluids and the surface te...

We present an explicit exact solution of Einstein’s equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has new surprising features. The universe is “closed” in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whol...

‎in this study‎, ‎properties of spectral characteristic are investigated for‎ ‎singular sturm-liouville operators in the case where an eigen‎ ‎parameter not only appears in the differential equation but is‎ ‎also linearly contained in the jump conditions‎. ‎also weyl function‎ ‎for considering operator has been defined and the theorems which‎ ‎related to uniqueness of solution of inverse proble...

The presence of S waves singularity points in low-symmetry anisotropic models significantly affects the topology slowness surfaces vicinity these and, consequently, results complications geometrical spreading. Thus, we analyse effect a point simple elliptical orthorhombic model with decoupled P wave.

The big bounce singularity of a simple 5D cosmological model is studied. Contrary to the standard big bang space-time singularity, this big bounce singularity is found to be an event horizon at which the scale factor and the mass density of the universe are finite, while the pressure undergoes a sudden transition from negative infinity to positive infinity. By using coordinate transformation it...

We study the inner-structure of a charged black-hole which is formed from the gravitational collapse of a self-gravitating charged scalar-field. Starting with a regular spacetime, we follow the evolution through the formation of an apparent horizon, a Cauchy horizon and a final central singularity. We find a null, weak, mass-inflation singularity along the Cauchy horizon, which is a precursor o...

We study the inner-structure of a charged black-hole which is formed from the gravitational collapse of a self-gravitating charged scalareld. Starting with a regular spacetime, we follow the evolution through the formation of an apparent horizon, a Cauchy horizon and a nal central singularity. We nd a null, weak, mass-in ation singularity along the Cauchy horizon, which is a precursor of a stro...

Abstract Structured light with customized topological patterns inspires diverse classical and quantum investigations underpinned by accurate detection techniques. However, the current schemes are limited to vortex beams a simple phase singularity. The precise recognition of general structured multiple singularities remains elusive. Here, we report deep learning (DL) framework that can unveil mu...