509 research outputs found

    Quantum amplification effect in a horizon fluctuations

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    The appearance of a few unevenly- spaced bright flashes of light on top of Hawking radiation is the sign of the amplification effect in black hole horizon fluctuations. Previous studies on this problem suffer from the lack of considering all emitted photons in the theoretical spectroscopy of these fluctuations. In this paper, we include all of the physical transition weights and present a consistent intensity formula. This modifies a black hole radiation pattern.Comment: 6 pages, 2 figure

    On Quantum Nature of Black-Hole Spacetime: A Possible New Source of Intense Radiation

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    Atoms and the planets acquire their stability from the quantum mechanical incompatibility of the position and momentum measurements. This incompatibility is expressed by the fundamental commutator [x, p_x]=i hbar, or equivalently, via the Heisenberg's uncertainty principle Delta x Delta p_x sim hbar. A further stability-related phenomenon where the quantum realm plays a dramatic role is the collapse of certain stars into white dwarfs and neutron stars. Here, an intervention of the Pauli exclusion principle, via the fermionic degenerate pressure, stops the gravitational collapse. However, by the neutron-star stage the standard quantum realm runs dry. One is left with the problematic collapse of a black hole. This essay is devoted to a concrete argument on why the black-hole spacetime itself should exhibit a quantum nature. The proposed quantum aspect of spacetime is shown to prevent the general-relativistic dictated problematic collapse. The quantum nature of black-hole spacetime is deciphered from a recent result on the universal equal-area spacing [=lambda_P^2 4 ln(3)] for black holes. In one interpretation of the emergent picture, an astrophysical black hole can fluctuate to sqrt{pi/ln(3)} approx 1.7 times its classical size, and thus allow radiation and matter to escape to the outside observers. These fluctuations I conjecture provide a new source, perhaps beyond Hawking radiation, of intense radiation from astrophysical black holes and may be the primary source of observed radiation from those galactic cores what carry black hole(s). The presented interpretation may be used as a criterion to choose black holes from black hole candidates.Comment: This essay received an "honorable mention" in the 1999 Essay Competition of the Gravity Research Foundation - Ed. Int. J. Mod. Phys. D (1999, in press). For Joseph Knech

    Chern-Simons Correlations on (2+1)D Lattice

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    We have computed the contribution of zero modes to the value of the number of particles in the model of discrete (2+1)-dimensional nonlinear Schr\"odinger equation. It is shown for the first time that in the region of small values of the Chern-Simons coefficient k there exists a universal attraction between field configurations. For k=2 this phenomenon may be a dynamic origin of the semion pairing in high temperature superconducting state of planar systems.Comment: 9 pages, 2 figures Sabj-class: Strongly Correlated Electron

    Spectrum of Charged Black Holes - The Big Fix Mechanism Revisited

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    Following an earlier suggestion of the authors(gr-qc/9607030), we use some basic properties of Euclidean black hole thermodynamics and the quantum mechanics of systems with periodic phase space coordinate to derive the discrete two-parameter area spectrum of generic charged spherically symmetric black holes in any dimension. For the Reissner-Nordstrom black hole we get A/4Gℏ=π(2n+p+1)A/4G\hbar=\pi(2n+p+1), where the integer p=0,1,2,.. gives the charge spectrum, with Q=±ℏpQ=\pm\sqrt{\hbar p}. The quantity π(2n+1)\pi(2n+1), n=0,1,... gives a measure of the excess of the mass/energy over the critical minimum (i.e. extremal) value allowed for a given fixed charge Q. The classical critical bound cannot be saturated due to vacuum fluctuations of the horizon, so that generically extremal black holes do not appear in the physical spectrum. Consistency also requires the black hole charge to be an integer multiple of any fundamental elementary particle charge: Q=±meQ= \pm me, m=0,1,2,.... As a by-product this yields a relation between the fine structure constant and integer parameters of the black hole -- a kind of the Coleman big fix mechanism induced by black holes. In four dimensions, this relationship is e2/ℏ=p/m2e^2/\hbar=p/m^2 and requires the fine structure constant to be a rational number. Finally, we prove that the horizon area is an adiabatic invariant, as has been conjectured previously.Comment: 21 pages, Latex. 1 Section, 1 Figure added. To appear in Class. and Quant. Gravit

    Trying to understand confinement in the Schroedinger picture

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    We study the gauge-invariant gaussian ansatz for the vacuum wave functional and show that it potentially possesses many desirable features of the Yang--Mills theory, like asymptotic freedom, mass generation through the transmutation of dimensions and a linear potential between static quarks. We point out that these (and other) features can be studied in a systematic way by combining perturbative and 1/n expansions. Contrary to the euclidean approach, confinement can be easily formulated and easily built in, if not derived, in the variational Schroedinger approach.Comment: 21 pages, 1 figure. Lecture given at the 4th St.Petersburg Winter School in Theoretical Physics, Feb. 22-28, 199

    Solution of gauge theories induced by fundamental representation scalars

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    Gauge theories induced by scalars in the fundamental representation of the U(Nc)gauge×U(Nf)globalU(N_c)_{gauge}\times U(N_f)_{global} group are investigated in the large NcN_c and NfN_f limit. A master field is defined from bilinears of the scalar field following an Eguchi-Kawai type reduction of spacetime. The density function for the master field satisfies an integral equation that can be solved exactly in two dimensions (D=2) and in a convergent series of approximations at D>2D>2. While at D=2 the system is in the same phase at all ϵ=Nc/Nf\epsilon=N_c/N_f, it undergoes a phase transition at a critical value, ϵc(D)\epsilon_c(D), for D>2D>2.Comment: 12 pages, LaTe

    SN1A data and the CMB of Modified Curvature at short and long distances

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    The SN1a data, although inconclusive, when combined with other observations makes a strong case that our universe is presently dominated by dark energy. We investigate the possibility that large distance modifications of the curvature of the universe would perhaps offer an alternative explanation of the observation. Our calculations indicate that a universe made up of no dark energy but instead, with a modified curvature at large scales, is not scale-invariant, therefore quite likely it is ruled out by the CMB observations. The sensitivity of the CMB spectrum is checked for the whole range of mode modifications of large or short distance physics. The spectrum is robust against modifications of short-distance physics and the UV cutoff when: the initial state is the adiabatic vacuum, and the inflationary background space is de Sitter.Comment: 13 pages, 2 eps figures, typos corrected, references added; to appear in Phys. Rev.

    Relativistic parsec-scale jets: I. Particle acceleration

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    We develop a theory of particle acceleration inside relativistic rotating electron-positron force-free jets with spiral magnetic fields. We considered perturbation of the stationary magnetic field structure and found that acceleration takes place in the regions where the Alfven resonant condition with the eigenmodes in the jet is fulfilled, i.e. where the local Alfven speed is equal to the phase speed of an eigenmode. The acceleration mechanism is regular acceleration by the electric field of the electromagnetic wave, which is the eigenmode of the force-free cylindrical jet: particles drift out of the region of the large wave amplitude near the Alfven resonant surface and gain energy. Acceleration in the strong electric field near the Alfven resonance and synchrotron losses combine to form a power-law energy spectrum of ultra-relativistic electrons and positrons with index between 2 and 3 depending upon the initial energy of the injected particles. The power law distribution ranges from 10 MeV to 1000 MeV.Comment: 14 pages, 4 figures; Astron. Astrophys. in pres

    Resistivity and 1/f Noise in Non-Metallic Phase Separated Manganites

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    A simple model is proposed to calculate resistivity, magnetoresistance, and noise spectrum in non-metallic phase-separated manganites containing small metallic droplets (magnetic polarons). The system is taken to be far from the percolation transition into a metallic state. It is assumed that the charge transfer occurs due to electron tunneling from one droplet to another through the insulating medium. As a result of this tunneling, the droplets acquire or lose extra electrons forming metastable two-electron and empty states. In the framework of this model, explicit expressions for dc conductivity and noise power of the system are derived. It is shown that the noise spectrum has 1/f form in the low-frequency range.Comment: 6 pages, 1 fugure include
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