Searcharxiv⌕ Search

arXiv subjects

V. V. Kiselev

Publications and source records attributed to V. V. Kiselev.

At least 55 records · Page 3Linked to original sources
arXiv2005

Ghost condensate model of flat rotation curves

An effective action of ghost condensate with higher derivatives creates a source of gravity and mimics a dark matter in spiral galaxies. We present a spherically symmetric static solution of Einstein--Hilbert equations with the ghost condensate at large distances, where flat rotation curves are reproduced in leading order over small ratio of two energy scales characterizing constant temporal and spatial derivatives of ghost field: $μ_*^2$ and $μ_\star^2$, respectively, with a hierarchy $μ_\star\ll μ_*$. We assume that a mechanism of hierarchy is provided by a global monopole in the center of galaxy. An estimate based on the solution and observed velocities of rotations in the asymptotic region of flatness, gives $μ_*\sim 10^{19}$ GeV and the monopole scale in a GUT range $μ_\star\sim 10^{16}$ GeV, while a velocity of rotation $v_0$ is determined by the ratio: $ \sqrt{2} v_0^2= μ_\star^2/μ_*^2$. A critical acceleration is introduced and naturally evaluated of the order of Hubble rate, that represents the Milgrom's acceleration.

gr-qc↗
arXiv2005

Heavy Quarkonium Physics

This report is the result of the collaboration and research effort of the Quarkonium Working Group over the last three years. It provides a comprehensive overview of the state of the art in heavy-quarkonium theory and experiment, covering quarkonium spectroscopy, decay, and production, the determination of QCD parameters from quarkonium observables, quarkonia in media, and the effects on quarkonia of physics beyond the Standard Model. An introduction to common theoretical and experimental tools is included. Future opportunities for research in quarkonium physics are also discussed.

hep-ph↗
arXiv2005

Entropy of BTZ black hole and its spectrum by quantum radial geodesics behind horizons

In the framework of thermal quantization of radial geodesics completely confined behind the horizons we calculate the entropy of BTZ black hole in agreement with the Bekenstein--Hawking relation. Particles in the BTZ black hole occupy the only quantum ground level. The quantization allow us to find a linear dependence of black hole mass versus its orbital momentum.

gr-qc↗
arXiv2005

Radial geodesics as a microscopic origin of black hole entropy. I: Confined under the Schwarzschild horizon

Causal radial geodesics with a positive interval in the Schwarzschild metric include a subset of trajectories completely confined under a horizon, which compose a thermal statistical ensemble with the Hawking-Gibbons temperature. The Bekenstein--Hawking entropy is given by an action at corresponding geodesics of particles with a summed mass equal to that of black hole in the limit of large mass.

gr-qc↗
arXiv2005

Radial geodesics as a microscopic origin of black hole entropy. III: Exercise with the Kerr-Newman black hole

We specify an angular motion on geodesics to reduce the problem to the case of radial motion elaborated in previous chapters. An appropriate value of entropy for a charged and rotating black hole is obtained by calculating the partition function on thermal geodesics confined under horizons. The quantum aggregation is classified in a similar way to the Reissner--Nordstrom black hole.

gr-qc↗
arXiv2004

Ghost condensate model of flat rotation curves

An effective action of ghost condensate with higher derivatives creates a source of gravity and mimics a dark matter in spiral galaxies. We present a spherically symmetric static solution of Einstein--Hilbert equations with the ghost condensate at large distances, where flat rotation curves are reproduced in leading order over small ratio of two energy scales characterizing constant temporal and spatial derivatives of ghost field: mu_*^2 and mu_\star^2, respectively, with a hierarchy mu_\star\ll μ_*. We assume that a mechanism of hierarchy is provided by a global monopole in the center of galaxy. An estimate based on the solution and observed velocities of rotations in the asymptotic region of flatness, gives mu_* ~ 10^{19} GeV and the monopole scale in a GUT range mu_\star ~ 10^{16} GeV, while a velocity of rotation v_0 is determined by the ratio: sqrt{2} v_0^2= mu_\star^2/mu_*^2. A critical acceleration is introduced and naturally evaluated of the order of Hubble rate, that represents the Milgrom's acceleration.

gr-qc↗
arXiv2004

Vector field and rotational curves in dark galactic halos

We study equations of a non-gauge vector field in a spherically symmetric static metric. The constant vector field with a scale arrangement of components: the time component about the Planck mass m_{Pl} and the radial component about M suppressed with respect to the Planck mass, serves as a source of metric reproducing flat rotation curves in dark halos of spiral galaxies, so that the velocity of rotation v_0 is determined by the hierarchy of scales: \sqrt{2} v_0^2= M/m_{Pl}, and M\sim 10^{12} GeV. A natural estimate of Milgrom's acceleration about the Hubble rate is obtained.

gr-qc↗
arXiv2004

Vector field as a quintessence partner

We derive generic equations for a vector field driving the evolution of flat homogeneous isotropic universe and give a comparison with a scalar filed dynamics in the cosmology. Two exact solutions are shown as examples, which can serve to describe an inflation and a slow falling down of dynamical ``cosmological constant'' like it is given by the scalar quintessence. An attractive feature of vector field description is a generation of ``induced mass'' proportional to a Hubble constant, which results in a dynamical suppression of actual cosmological constant during the evolution.

gr-qc↗
arXiv2003

Possibility of Measuring the CP-Violation gamma-parameter in Decays of Xi_bc Baryons

The model-independent method based on the triangle ideology is implemented to extract the CKM-matrix angle gamma in the decays of doubly heavy baryons containing the charmed and beauty quarks. We analyze a color structure of diagrams and conditions for reconstructing two reference-triangles by tagging the flavor and CP eigenstates of neutral D mesons in the fixed exclusive channels. The characteristic branching ratios are evaluated in the framework of a potential model setting a parametric dependence on the hadronic matrix elements for the decay rates.

hep-ph↗
arXiv2003

A gluon condensate term in a heavy quark mass

We investigate a connection between a renormalon ambiguity of heavy quark mass and the gluon condensate contribution into the quark dispersion law related with a virtuality defining a displacement of the heavy quark from the perturbative mass-shell, which happens inside a hadron.

hep-ph↗
arXiv2003

Electroweak symmetry breaking in Higgs mechanism with composite operators and solution of naturalness

Introducing a source for a bi-local composite operator motivated by the perturbative expansion in gauge couplings, we calculate its effective potential in the renormalization group of Standard Model with no involvement of technicolor. The potential indicates the breaking of electroweak symmetry below a scale M due to a nonzero vacuum expectation value of neutral component for the SU(2)-doublet operator. At virtualities below a cut off Λwe introduce the local higgs approximation for the effective fields of sources coupled to the composite operators. The value of Λ\approx 600 GeV is fixed by the measured masses of gauge vector bosons. The exploration of equations for infrared fixed points of calculated Yukawa constants allows us to evaluate the masses of heaviest fermion generation with a good accuracy, so that m_t(m_t) = 165\pm 4 GeV, m_b(m_b) = 4.18\pm 0.38 GeV and m_τ(m_τ) = 1.78\pm 0.27 GeV. After a finite renormalization of effective fields for the sources of composite operators, the parameters of effective Higgs field potential are calculated at the scale of matching with the local theory Λ. The fixed point for the Yukawa constant of t quark and the matching condition for the null effective potential at M drive the M value to the GUT scale. The equation for the infrared fixed point of quartic self-action allows us to get estimates for two almost degenerate scalar particles with m_H= 306\pm 5 GeV, while third scalar coupled with the tau lepton is more heavy: m_{H_τ} = 552\pm 9 GeV. Some phenomenological implications of the offered approach describing the effective scalar field, and a problem on three fermion generations are discussed.

hep-ph↗
arXiv2003

Quintessential solution of dark matter rotation curves and its simulation by extra dimensions

On the base of an exact solution for the static spherically symmetric Einstein equations with the quintessential dark matter, we explain the asymptotic behavior of rotation curves in spiral galaxies. The parameter of the quintessence state, i.e. the ratio of its pressure to the density is tending to -1/3. We present an opportunity to imitate the relevant quintessence by appropriate scalar fields in the space-time with extra 2 dimensions.

gr-qc↗