Concatenation of Scales Below 1 eV

There are (at least) four numbers of physical and cosmological significance whose inferred values, when expressed in mass units, cluster in a window below 1 eV. These are: the neutrino mass, the neutrino chemical potential, the cosmological constant, and the size of two extra dimensions (if the fundamental scale of gravity is 1-10 TeV). In this note, we imagine ways in which these four numbers could all be connected.Comment: 9 pages, LaTeX; factor of 10^{27} corrected; results unaffecte

Zeta function regularization in de Sitter space: the Minkowski limit

We study an integral representation for the zeta function of the one-loop effective potential for a minimally coupled massive scalar field in D-dimensional de Sitter spacetime. By deforming the contour of integration we present it in a form suitable for letting the de Sitter radius tend to infinity, and we demonstrate explicitly for the case D=2 that the quantities $\zeta( 0 )$ and $\zeta'( 0 )$ have the appropriate Minkowski limits.Comment: TeX, 14 pages, a reference adde

Warp Factors and Extended Sources in Two Transverse Dimensions

We study the solutions of the Einstein equations in (d+2)-dimensions, describing parallel p-branes (p=d-1) in a space with two transverse dimensions of positive gaussian curvature. These solutions generalize the solutions of Deser and Jackiw of point particle sources in (2+1)-dimensional gravity with cosmological constant. Determination of the metric is reduced to finding the roots of a simple algebraic equation. These roots also determine the nontrivial "warp factors" of the metric at the positions of the branes. We discuss the possible role of these solutions and the importance of "warp factors" in the context of the large extra dimensions scenario.Comment: 11 pages, LaTeX; References and acknowledgments adde

Tachyons as a Consequence of Light-Cone Reflection Symmetry

We introduce a new symmetry, Light-Cone Reflection (LCR), which interchanges timelike and spacelike intervals. Our motivation is to provide a reason, based on symmetry, why tachyons might exist, with emphasis on application to neutrinos. We show that LCR, combined with translations, leads to a much larger symmetry. We construct an LCR-invariant Lagrangian, and discuss some of its properties. In a simple example, we find complete symmetry in the spectrum between tachyons and ordinary particles. We also show that the theory allows for the introduction of a further gauge invariance related to chiral symmetry.Comment: To be published in Symmetry special issue: "Tachyons and Fundamental Symmetries