15,189 research outputs found

    How much negative energy does a wormhole need?

    Full text link
    It is known that traversible wormholes require negative energy density. We here argue how much negative energy is needed for wormholes, using a local analysis which does not assume any symmetry. and in particular allows dynamic (non-stationary) but non-degenerate wormholes. We find that wormholes require two constraints on the energy density, given by two independent components of the Einstein equation.Comment: 6 pages, no figure

    Traversable wormholes from massless conformally coupled scalar fields

    Get PDF
    The massless conformally coupled scalar field is characterized by the so-called "new improved stress-energy tensor", which is capable of classically violating the null energy condition. When coupled to Einstein gravity we find a three-parameter class of exact solutions. These exact solutions include the Schwarzschild geometry, assorted naked singularities, and a large class of traversable wormholes.Comment: 11 Pages, plain LaTeX2e, uses graphics.sty, three *.eps figure

    Wormholes and negative energy from the gravitationally squeezed vacuum

    Get PDF
    Minkowski-signature wormhole solutions of the Einstein field equations require the existence of negative energy density in the vicinity of their throats. We point out that the gravitational interaction automatically generates squeezed vacuum states of matter, which by their nature, entail negative energy and, thus, provide a natural source for maintaining this class of wormholes

    Broadcasting and CATV: The Beauty and the Bane of Major College Football

    Get PDF
    Discusses: (1) the existing broadcast arrangements for major college football, (2) the historical forces that have culminated in the current pattern of major college football programming, and (3) the economic implications of the broadcasting of those games. Then explores the potential impact of cable television (CATV) on major college football telecasting

    Splitting the Wino Multiplet by Higher-Dimensional Operators in Anomaly Mediation

    Full text link
    In a class of AMSB models, the splitting in the Wino multiplet turns out to be very small, such as the often-quoted 170 MeV in minimal AMSB, which originates from MSSM loops. Such a small mass gap is potentially a window into higher scale physics, as it may be sensitive to higher-dimensional operators. We show that still within AMSB one can get a much larger splitting in the Wino multiplet--a few GeV--if the scale of the new physics is comparable to the gravitino mass (which is indeed often the scale of new physics in anomaly mediation).Comment: 18 pages; v2: references added, matching journal versio
    corecore