4,553 research outputs found

    A Relativistic Description of Gentry's New Redshift Interpretation

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    We obtain a new expression of the Friedmann-Robertson-Walker metric, which is an analogue of a static chart of the de Sitter space-time. The reduced metric contains two functions, M(T,R)M(T,R) and Ψ(T,R)\Psi(T,R), which are interpreted as, respectively, the mass function and the gravitational potential. We find that, near the coordinate origin, the reduced metric can be approximated in a static form and that the approximated metric function, Ψ(R)\Psi(R), satisfies the Poisson equation. Moreover, when the model parameters of the Friedmann-Robertson-Walker metric are suitably chosen, the approximated metric coincides with exact solutions of the Einstein equation with the perfect fluid matter. We then solve the radial geodesics on the approximated space-time to obtain the distance-redshift relation of geodesic sources observed by the comoving observer at the origin. We find that the redshift is expressed in terms of a peculiar velocity of the source and the metric function, Ψ(R)\Psi(R), evaluated at the source position, and one may think that this is a new interpretation of {\it Gentry's new redshift interpretation}.Comment: 11 pages. Submitted to Modern Physics Letters

    SQE-ezed Out: SRA, Status and Stasis

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    This article considers the proposals to introduce the Solicitors Qualifying Examination (SQE) from a widening participation angle. It argues that the SQE will not increase access to the solicitors profession but will instead perpetuate patterns of subordination and risks further silencing already unrepresented social groups. The paper examines the widening participation agenda in relation to the solicitors profession concluding that there is little incentive or real commitment to widening access. The paper then examines the SQE and the widening access rhetoric which has, for a time at least, accompanied it and questions whether the assertions and assumptions about how the SQE can improve diversity in the profession really hold true

    Non-topological solitons as nucleation sites for cosmological phase transitions

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    I consider quantum field theories that admit charged non-topological solitons of the Q-ball type, and use the fact that in a first-order cosmological phase transition, below the critical temperature, there is a value of the soliton charge above which the soliton becomes unstable and expands, converting space to the true vacuum, much like a critical bubble in the case of ordinary tunneling. Using a simple model for the production rate of Q-balls through charge accretion during a random walk out of equilibrium, I calculate the probability for the formation of critical charge solitons and estimate the amount of supercooling needed for the phase transition to be completed.Comment: 20 pages, 2 figures, some comments and references adde

    Large Scale Inhomogeneities from the QCD Phase Transition

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    We examine the first-order cosmological QCD phase transition for a large class of parameter values, previously considered unlikely. We find that the hadron bubbles can nucleate at very large distance scales, they can grow as detonations as well as deflagrations, and that the phase transition may be completed without reheating to the critical temperature. For a subset of the parameter values studied, the inhomogeneities generated at the QCD phase transition might have a noticeable effect on nucleosynthesis.Comment: 15 LaTeX pages + 6 PostScript figures appended at the end of the file, HU-TFT-94-1

    Natural Inflation From Fermion Loops

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    ``Natural'' inflationary theories are a class of models in which inflation is driven by a pseudo-Nambu-Goldstone boson. In this paper we consider two models, one old and one new, in which the potential for inflation is generated by loop effects from a fermion sector which explicitly breaks a global U(1)U(1) symmetry. In both models, we retrieve the ``standard'' natural inflation potential, V(θ)=Λ4[1+cos(θ/μ)]V\left(\theta\right) = \Lambda^4\left[1 + \cos\left(\theta / \mu\right)\right], as a limiting case of the exact one-loop potential, but we carry out a general analysis of the models including the limiting case. Constraints from the COBE DMR observation and from theoretical consistency are used to limit the parameters of the models, and successful inflation occurs without the necessity of fine-tuning the parameters.Comment: (Revised) 15 pages, LaTeX (revTeX), 8 figures in uuencoded PostScript format. Version accepted for publication in Phys. Rev. D 15. Corrected definition of power spectrum and added three reference

    Supersymmetric Inflation with the Ordinary Higgs?

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    We consider a model of D-term inflation in which the inflaton coincides with the standard Higgs doublet. Non-renormalizable terms are controlled by a discrete R-symmetry of the superpotential. We consider radiative corrections to the scalar potential and find that Higgs inflation in the slow-roll approximation is viable and consistent with CMB data, although with a rather large value of the non-renormalizable coupling involved.Comment: 7 pages, 1 figure, published version, comments and reference added, typos and factor of 2 corrected

    Displacement energy of unit disk cotangent bundles

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    We give an upper bound of a Hamiltonian displacement energy of a unit disk cotangent bundle DMD^*M in a cotangent bundle TMT^*M, when the base manifold MM is an open Riemannian manifold. Our main result is that the displacement energy is not greater than Cr(M)C r(M), where r(M)r(M) is the inner radius of MM, and CC is a dimensional constant. As an immediate application, we study symplectic embedding problems of unit disk cotangent bundles. Moreover, combined with results in symplectic geometry, our main result shows the existence of short periodic billiard trajectories and short geodesic loops.Comment: Title slightly changed. Close to the version published online in Math Zei
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