27 research outputs found

    Beyond the Singularity of the 2-D Charged Black Hole

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    Two dimensional charged black holes in string theory can be obtained as exact (SL(2,R)xU(1))/U(1) quotient CFTs. The geometry of the quotient is induced from that of the group, and in particular includes regions beyond the black hole singularities. Moreover, wavefunctions in such black holes are obtained from gauge invariant vertex operators in the SL(2,R) CFT, hence their behavior beyond the singularity is determined. When the black hole is charged we find that the wavefunctions are smooth at the singularities. Unlike the uncharged case, scattering waves prepared beyond the singularity are not fully reflected; part of the wave is transmitted through the singularity. Hence, the physics outside the horizon of a charged black hole is sensitive to conditions set behind the past singularity.Comment: 19 pages, 5 figures; v2: refs added, minor typos corrected; v3: references on the infinite blue shift at the inner horizon and minor corrections adde

    Black-Hole-Wave Duality in String Theory

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    Extreme 4-dimensional dilaton black holes embedded into 10-dimensional geometry are shown to be dual to the gravitational waves in string theory. The corresponding gravitational waves are the generalization of pp-fronted waves, called supersymmetric string waves. They are given by Brinkmann metric and the two-form field, without a dilaton. The non-diagonal part of the metric of the dual partner of the wave together with the two-form field correspond to the vector field in 4-dimensional geometry of the charged extreme black holes.Comment: 12 pages, LaTeX, preprint UG-3/94, SU-ITP-94-11, QMW-PH-94-1

    Slowly rotating black holes in the Horava-Lifshitz gravity

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    We investigate slowly rotating black holes in the Ho\v{r}ava-Lifshitz (HL) gravity. For ΛW=0\Lambda_W=0 and λ=1\lambda=1, we find a slowly rotating black hole of the Kehagias-Sfetsos solution in asymptotically flat spacetimes. We discuss their thermodynamic properties by computing mass, temperature, angular momentum, and angular velocity on the horizon.Comment: 12 pages, no figures, version to appear in EPJ

    Calculating the annual input of organic matter to soil from radiocarbon measurements

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    Measurements of total organic C, deltaC-13 and deltaC-14 are given for topsoils taken from six experimental sites in southern England. At each site, some of the samples were collected before and some after the thermonuclear tests of the early 1960s, so that pre- and post-bomb samples could be compared for radiocarbon content. The current Rothamsted model for the turnover of organic C in soil gave an acceptable fit to the data from five of the sites, apart from one aberrant radiocarbon measurement. The annual input of C to the topsoil was calculated for the five sites from these fits; the values obtained were: 0.15 t C ha-1 a-1 for a site on silty clay loam, kept bare by hand weeding since 1870; 0.2 for unmanured spring barley growing on a sandy loam; 2.95 for a fertilized all-arable rotation on a loamy sand; 1.9 for the same fertilized all-arable rotation on a silty loam and 2.5 from this rotation on a calcareous silty loam. The corresponding values for Net Primary Production at the five sites were 0.15, 0.76, 5.16, 5.71 and 5.46 t C ha-1 a-1. In fitting the model to the radiocarbon data it was necessary to postulate that all these sites contained substantial quantities of biologically-inert organic matter, ranging from 2.2 to 10.0 t C ha-1
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