387 research outputs found
An Axisymmetric Object-Based Search for a Flat Compact Dimension
A method is presented to search for a hypertorus symmetry axis by the
alignment of distant objects. This offers greater sensitivity than previously
proposed object-based methods that rely on accurate true distances. When
applied to the catalog of objects with z > 1, we find no evidence for a compact
dimension. We deduce a lower limit to the compact dimension size D > 0.9 of the
distance to the cosmic horizon. This is consistent with independent constraints
from the recent analysis of the WMAP microwave background data.Comment: 12 pages, 10 figures, minor revision, accepted by JCA
Gamma-Ray Bursts via Pair Plasma Fireballs from Heated Neutron Stars
In this paper we model the emission from a relativistically expanding
electron-positron pair plasma fireball originating near the surface of a heated
neutron star. This pair fireball is deposited via the annihilation of neutrino
pairs emanating from the surface of the hot neutron star. The heating of
neutron stars may occur in close neutron star binary systems near their last
stable orbit. We model the relativistic expansion and subsequent emission of
the plasma and find 10^51 to 10^52 ergs in gamma-rays are produced with
spectral and temporal properties consistent with observed gamma-ray bursts.Comment: 5 pages, 3 figures. Submitted to the Conference Proceedings of the
5th Huntsville Gamma-Ray Burst Symposiu
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