Thickness of the strangelet-crystal crust of a strange star

It has recently been pointed out that if the surface tension of quark matter is low enough, the surface of a strange star will be a crust consisting of a crystal of charged strangelets in a neutralizing background of electrons. This affects the behavior of the surface, and must be taken into account in efforts to observationally rule out strange stars. We calculate the thickness of this ``mixed phase'' crust, taking into account the effects of surface tension and Debye screening of electric charge. Our calculation uses a generic parametrization of the equation of state of quark matter. For a reasonable range of quark matter equations of state, and surface tension of order a few MeV/fm^2, we find that the preferred crystal structure always involves spherical strangelets, not rods or slabs of quark matter. We find that for a star of radius 10 km and mass 1.5 Msolar, the strangelet-crystal crust can be from zero to hundreds of meters thick, the thickness being greater when the strange quark is heavier, and the surface tension is smaller. For smaller quark stars the crust will be even thicker.Comment: 10 pages, LaTe

Implications and Policy Options of California's Reliance on Natural Gas

Examines existing and currently anticipated infrastructure, rising gas prices, and recurring supply problems, and looks at options to alleviate the problem. Part of a series of research reports that examines energy issues facing California

Peeling Back the Onion of Cyber Espionage after Tallinn 2.0

Tallinn 2.0 represents an important advancement in the understanding of international law’s application to cyber operations below the threshold of force. Its provisions on cyber espionage will be instrumental to states in grappling with complex legal problems in the area of digital spying. The law of cyber espionage as outlined by Tallinn 2.0, however, is substantially based on rules that have evolved outside of the digital context, and there exist serious ambiguities and limitations in its framework. This Article will explore gaps in the legal structure and consider future options available to states in light of this underlying mismatch

Charged False Vacuum Bubbles and the AdS/CFT Correspondence

We initiate a study of cosmology within the framework of Maldacena's AdS/CFT correspondence. We present a comprehensive analysis of the classical motion of a charged domain wall that separates an external Reissner-Nordstrom region of spacetime (with small or vanishing cosmological constant) from an internal de-Sitter region. The possible associated spacetime diagrams are drawn, although in the classical case, an unambiguous prediction of what occurs at late times in the interior region is not possible, since singularities and Cauchy horizons form. We argue that, when the asymptotic region is anti-de Sitter, the AdS/CFT correspondence gives a prescription for resolving the curvature singularities and evolving solutions across the expected Cauchy horizon. Some of our solutions contain inflating interiors, and we provide evidence these can be patched onto solutions with smooth initial data, circumventing an obstacle found by Farhi and Guth to creating an inflating universe in the laboratory.Comment: 21 pages, 6 figures, latex, references and some comments adde