4,379 research outputs found

    Thermonuclear burn-up in deuterated methane CD4CD_4

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    The thermonuclear burn-up of highly compressed deuterated methane CD4_4 is considered in the spherical geometry. The minimal required values of the burn-up parameter x=ρ0rfx = \rho_0 \cdot r_f are determined for various temperatures TT and densities ρ0\rho_0. It is shown that thermonuclear burn-up in CD4CD_4 becomes possible in practice if its initial density ρ0\rho_0 exceeds 5103\approx 5 \cdot 10^3 gcm3g \cdot cm^{-3}. Burn-up in CD2_2T2_2 methane requires significantly (\approx 100 times) lower compressions. The developed approach can be used in order to compute the critical burn-up parameters in an arbitrary deuterium containing fuel

    Traversable Wormholes and Black Hole Complementarity

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    Black hole complementarity is incompatible with the existence of traversable wormholes. In fact, traversable wormholes cause problems for any theory where information comes out in the Hawking radiation.Comment: 4 pages, CALT-68-193

    Quantization of the black hole area as quantization of the angular momentum component

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    In transforming from Schwarzschild to Euclidean Rindler coordinates the Schwarzschild time transforms to a periodic angle. As is well-known, this allows one to introduce the Hawking temperature and is an origin of black hole thermodynamics. On the other hand, according to quantum mechanics this angle is conjugate to the zz component of the angular momentum. From the commutation relation and quantization condition for the angular momentum component it is found that the area of the horizon of a Schwarzschild black hole is quantized with the quantum ΔA=8πlP2\Delta A = 8\pi l_P^{2}. It is shown that this conclusion is also valid for a generic Kerr-Newman black hole.Comment: 4 pages (revtex), no figures; a boundary condition for the differential equation (15) added; the absent of the remnants in the approach noted; a reference added; accepted by Physical Review D for publicatio

    On the bound state of the antiproton-deuterium-tritium ion

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    The properties of the weakly-bound S(L=0)S(L = 0)-state in the pˉdt\bar{p}dt ion are investigated with the use of the results of highly accurate computations. The hyperfine structure splitting of this ion is investigated. We also evaluate the life-time of the pˉdt\bar{p}dt ion against the nuclear (d,t)(d,t)-fusion and discuss a possibility to evaluate the corresponding annihilation rate(s)

    Accretion of non-minimally coupled generalized Chaplygin gas into black holes

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    The mass evolution of Schwarzschild black holes by the absorption of scalar fields is investigated in the scenario of the generalized Chaplygin gas (GCG). The GCG works as a unification picture of dark matter plus dark energy that naturally accelerates the expansion of the Universe. Through elements of the quasi-stationary approach, we consider the mass evolution of Schwarzschild black holes accreted by non-minimally coupled cosmological scalar fields reproducing the dynamics of the GCG. As a scalar field non-minimally coupled to the metrics, such an exotic content has been interconnected with accreting black holes. The black hole increasing masses by the absorption of the gas reflects some consistence of the accretion mechanism with the hypothesis of the primordial origin of supermassive black holes. Our results effectively show that the non-minimal coupling with the GCG dark sector accelerates the increasing of black hole masses. Meanwhile some exotic features can also be depicted for specific ranges of the non-minimal coupling in which the GCG dynamics is substantially modified.Comment: 13 pages, 03 figure

    Soap Bubbles in Outer Space: Interaction of a Domain Wall with a Black Hole

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    We discuss the generalized Plateau problem in the 3+1 dimensional Schwarzschild background. This represents the physical situation, which could for instance have appeared in the early universe, where a cosmic membrane (thin domain wall) is located near a black hole. Considering stationary axially symmetric membranes, three different membrane-topologies are possible depending on the boundary conditions at infinity: 2+1 Minkowski topology, 2+1 wormhole topology and 2+1 black hole topology. Interestingly, we find that the different membrane-topologies are connected via phase transitions of the form first discussed by Choptuik in investigations of scalar field collapse. More precisely, we find a first order phase transition (finite mass gap) between wormhole topology and black hole topology; the intermediate membrane being an unstable wormhole collapsing to a black hole. Moreover, we find a second order phase transition (no mass gap) between Minkowski topology and black hole topology; the intermediate membrane being a naked singularity. For the membranes of black hole topology, we find a mass scaling relation analogous to that originally found by Choptuik. However, in our case the parameter pp is replaced by a 2-vector p\vec{p} parametrizing the solutions. We find that MassppγMass\propto|\vec{p}-\vec{p}_*|^\gamma where γ0.66\gamma\approx 0.66. We also find a periodic wiggle in the scaling relation. Our results show that black hole formation as a critical phenomenon is far more general than expected.Comment: 15 pages, Latex, 4 figures include
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