English
Related papers

Related papers: Black disk radius constrained by unitarity

200 papers

We study the effect of gluon number fluctuations (Pomeron loops) on the impact parameter behavior of the scattering amplitude in the fixed coupling case. We demonstrate that the dipole-hadron cross-section computed from gluon number…

High Energy Physics - Phenomenology · Physics 2010-05-19 Wenchang Xiang

Using the result obtained in a prevoius paper, in which I found an upper limit on the region of particle creation in the vicinity of the event horizon of a Schwarzschild black hole, and by assuming that all the created energy will be…

General Relativity and Quantum Cosmology · Physics 2010-04-30 M. B. Altaie

An exact solution representing black holes in an expanding universe is found. The black holes are maximally charged and the universe is expanding with arbitrary equation of state. It is an exact solution of the Einstein-scalar-Maxwell…

General Relativity and Quantum Cosmology · Physics 2010-06-14 Gary W. Gibbons , Kei-ichi Maeda

In this note, I argue that tidal effects generically limit the kinetic energy of a single massive elementary particle in the vicinity of a compact object. As the kinetic energy is increased, the differences in the tidal potential over a…

General Relativity and Quantum Cosmology · Physics 2024-01-24 Justin C. Feng

Caustic rings of dark matter with $\textit{tricusp}$ cross-section were predicted to lie in the galactic disk. Their radii increase on cosmological time scales at a rate of order $1$ kpc/Gyr. When a caustic ring passes through the orbit of…

Astrophysics of Galaxies · Physics 2018-11-21 Sankha S. Chakrabarty , Pierre Sikivie

The process of gravitational collapse excites the fields propagating in the background geometry and gives rise to thermal radiation. We demonstrate by explicit calculations that the density matrix corresponding to such radiation actually…

General Relativity and Quantum Cosmology · Physics 2015-09-30 Anshul Saini , Dejan Stojkovic

When dark matter structures form and equilibrate they have to release a significant amount of energy in order to obey the virial theorem. Since dark matter is believed to be unable to radiate, this implies that some of the accreted dark…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-03 Steen H. Hansen

The causality and/or the energy-momentum constraints on the amplitudes of high energy processes are generalized to QCD. The constraints imply that the energetic parton may experience at most one inelastic collision only and that the number…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Blok , L. Frankfurt

Unified dark matter models are appealing in that they describe the dark sector in terms of a single component. They however face problems when attempting to account for structure formation: in the linear regime, density fluctuations can…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-16 Amr El-Zant

Acceleration of protons in the active galactic nuclei is considered. The largest energy is achieved by protons during centrifugal acceleration in the magnetosphere of the central machine. When the proton accelerated in the magnetosphere of…

High Energy Astrophysical Phenomena · Physics 2019-12-03 A. A. Gunya , Y. N. Istomin

Galactic center black holes appear to be nearly universally surrounded by dense stellar clusters. When these black holes go through an active accretion phase, the multiple components of the accretion disk, stellar cluster, and black hole…

Solar and Stellar Astrophysics · Physics 2020-02-12 Morgan MacLeod , Douglas N. C. Lin

Dark energy is modelled by a Bose-Einstein gas of particles with an attractive interaction. It is coupled to cold dark matter, within a flat universe, for the late-expansion description, producing variations in particle-number densities.…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-11 Hiram E. Lucatero--Villaseñor , German Izquierdo , Jaime Besprosvany

Based on the non-linear logistic equation we study, in a qualitative and semi-quantitative way, the evolution with energy and saturation of the elastic differential cross-section in $pp(\bar{p}p)$ collisions at high energy. Geometrical…

High Energy Physics - Phenomenology · Physics 2010-05-21 P. Brogueira , J. Dias de Deus

One of the greatest challenges of science is to understand the current accelerated expansion of the Universe. In this work, we show that by considering the quantum nature of the gravitational field, its wavelength can be associated with an…

General Physics · Physics 2022-11-08 Tonatiuh Matos , Laura L-Parrilla

We have extended previous analytical studies of the interaction of dark halos with galactic disks by introducing for the halo particles anisotropic distribution functions in phase space. For this purpose we have employed the shearing sheet…

Astrophysics · Physics 2009-11-11 B. Fuchs , E. Athanassoula

Radiation reaction acting on a charged particle moving at a stable circular orbit of a magnetized black hole can lead to the shift of the orbital radius outwards from the black hole. The effect causes increase of the energy and angular…

General Relativity and Quantum Cosmology · Physics 2018-11-06 Arman Tursunov , Martin Kološ , Zdeněk Stuchlík

We present numerical simulations of misaligned discs around a spinning black hole covering a range of parameters. Previous simulations have shown that discs that are strongly warped by a forced precession -- in this case the Lense-Thirring…

High Energy Astrophysical Phenomena · Physics 2021-03-24 Anagha Raj , Chris Nixon , Suzan Dogan

Accretion discs around black holes can become warped by Lense-Thirring precession if the disc is tilted with respect to the black hole spin vector. When the disc viscosity is sufficiently large that warp propagation is diffusive, the inner…

High Energy Astrophysical Phenomena · Physics 2022-03-14 N. C. Drewes , C. J. Nixon

Observations show that the expansion of the Universe is accelerating. This requires that the dominant constituent of matter in the Universe has some unusual properties like negative pressure. This exotic component has been given the name…

Popular Physics · Physics 2019-01-17 Manvendra Pratap Rajvanshi , Tuneer Chakraborty , J. S. Bagla

In three spatial dimensions, the Compton wavelength $(R_C \propto M^{-1}$) and Schwarzschild radius $(R_S \propto M$) are dual under the transformation $M \rightarrow M_{P}^2/M$, where $M_{P}$ is the Planck mass. This suggests that there is…

General Relativity and Quantum Cosmology · Physics 2019-01-01 Matthew J. Lake , Bernard Carr