We resume former discussions of the question, whether the spin-spin repulsion and the gravitational attraction of two aligned black holes can balance each other. To answer the question we formulate a boundary value problem for two separate (Killing-) horizons and apply the inverse (scattering) method to solve it. Making use of results of Manko, Ruiz and Sanabria-Gómez and a novel black hole cri...

The paper discusses the experimental and finite element investigation into the failure mechanisms of uniply graphite-epoxy composite plates with circular holes loaded in uniaxial compression. The effect of hole size on the failure mode is established. Test specimens composed of a single layer of uniply graphite-epoxy sandwiched between two layers of transparent polyetherimide plastic were desig...

A bstract In this work, we develop a perturbative method to describe the behavior of chiral condensate around spherical black hole whose mass is astrophysically realistic. We use inverse as expansion parameter for our series. test in case Schwarzschild hole, and find that it agrees well with previous numerical results. For an astrophysical-mass leading order contribution much larger (in most sp...

Simple calculations indicate that the partition function for a black hole is defined only if the temperature is fixed on a finite boundary. Consequences of this result are discussed. 1 The Black Hole Partition Function From the work of Gibbons and Hawking in the late 1970’s came a very simple prescription for the computation of the temperature of a static black hole [1]: • Write the black hole ...

We carry out a systematic study of collective spin- and charge excitations for the canonical single-band Hubbard, $t$-$J$-$U$, $t$-$J$ models high-temperature copper-oxide superconductors, both on electron- hole-doped side phase diagram. Recently developed variational wave function approach, combined with expansion in inverse number fermionic flavors, is employed. All three exhibit substantial ...

In the present research, the mixed-mode fracture mechanics analysis in a plate with central hole under tensile loading is considered. It is assumed that a plate containing two symmetrical hole-edge cracks is bonded with two dissimilar planes. The stress intensity factors at the crack tips are calculated. The problem is modeled in Casca software and this model is analyzed with Franc software. Th...

Roll forming process is used for manufacturing sheet metal parts by successive bending and creating the final shape with gradual deformation. In this article, deformation of a pre-punched sheet due to the roll forming process was studied. Two main defects in the roll forming process are ovality of holes and bow defect. The ovality of the hole is influenced by the process parameters including sh...

Abstract Electron-hole asymmetry is a fundamental property in solids that can determine the nature of quantum phase transitions and regime operation for devices. The observation electron-hole graphene recently twisted moiré heterostructures has spurred interest into whether it stems from single-particle effects or correlations, which are core to emergence intriguing phases systems. Here, we rep...

I review the observed temporal X-ray properties of Galactic black hole candidates and the status of theoretical modeling of these properties. Like spectral X-ray properties, which has so far attracted most of the attention, the temporal properties, such as power spectral density, hard X-ray time lags, and coherence functions, contain information on some of the same physical properties of invers...