Sensitivity of Astrophysical Observations to Gravity-Induced Wave Dispersion in Vacuo
ArXiv astro-ph/9810483 (1998)
Abstract:
We discuss possible signatures of quantum gravity for the propagation of light, including an energy-dependent velocity (refractive index), dispersion in velocity at a given energy, and birefringence. We also compare the sensitivities of different astrophysical observations, including BATSE data on GRB 920229, BeppoSAX data on GRB 980425, the possible HEGRA observation of GRB 920925c, and Whipple observations of the active galaxy Mrk 421. Finally, we discuss the prospective sensitivities of AMS and GLAST.Sensitivity of Astrophysical Observations to Gravity-Induced Wave Dispersion in Vacuo
(1998)
The Fayet-Iliopoulos term in Type-I string theory and m-theory
PHYS LETT B 437:3-4 (1998) 318-324
Abstract:
The magnitude of the Fayet-Iliopoulos term is calculated for compactifications of Type-I string theory and Horava-Witten M-theory in which then exists a pseudo-anomalous U(1)(x). Contrary to various conjectures, it is found that in leading order in the perturbative expansion around the weakly-coupled M-theory or Type-I limits, a result identical to that of the weakly-coupled E-8 x E-8 heterotic string is obtained. The result is independent of the values chosen for the Type-I string scale or the size of the M-theory 11th dimension, only depending upon Newton's constant and the unified gauge coupling. (C) 1998 Published by Elsevier Science B.V. All rights reserved.On the four-dimensional effective action of strongly coupled heterotic string theory
Nuclear Physics B Elsevier 532:1-2 (1998) 43-82
Tests of quantum gravity from observations of γ-ray bursts
Nature Springer Science and Business Media LLC 395:6701 (1998) 525-525