The string spectrum on the horizon of a non-extremal black hole

We investigate the conformal string $\sigma$-model corresponding to a general five-dimensional non-extremal black hole solution. In the horizon region the theory reduces to an exactly solvable conformal field theory. We determine the modular invariant spectrum of physical string states, which expresses the Rindler momentum operator in terms of three charges and string oscillators. For black holes with winding and Kaluza-Klein charges, we find that states made with only right-moving excitations have ADM mass equal to the black hole ADM mass, and thus they can be used as sources of the gravitational field. A discussion on statistical entropy is included.Comment: 17 pages, harvmac (minor corrections

Reducing wildland fire hazard exploiting complex network theory. A case study analysis

We discuss a new systematic methodology to mitigate wildland fire hazard by appropriately distributing fuel breaks in space. In particular, motivated by the concept of information flow in complex networks we create a hierarchical allocation of the landscape patches that facilitate the fire propagation based on the Bonacich centrality. Reducing the fuel load in these critical patches results to lower levels of fire hazard. For illustration purposes we apply the proposed strategy to a real case of wildland fire. In particular we focus on the wildland fire that occurred in Spetses Island, Greece in 1990 and burned the one third of the forest. The efficiency of the proposed strategy is compared against the benchmark of random distribution of fuel breaks for a wide range of fuel breaks densities

Construction of SL(2,Z) invariant amplitudes in type IIB superstring theory

The construction of $SL(2,Z)$ invariant amplitudes that generalizethe Virasoro amplitude is investigated in detail. We describe a number of mathematical properties that characterize the simplest example, and present pieces of evidence that it represents the tree-level four-graviton scattering amplitude in membrane theory on ${\bf R}^9\times T^2$ in the limit that the torus area goes to zero. In particular, we show that the poles of the $S$-dual amplitude are in precise correspondence with the states of membrane theory that survive in the type IIB limit. These are shown to be the states that span the Cartan subspaces of area preserving diffeomorphisms of the 2-torus; all other states become infinitely massive, and membrane world-volume theory acquires the structure of a free theory.Comment: new section on effective action, small corrections. 23 pages, harvma

On black hole singularities in quantum gravity

We show that absence of space-like boundaries in 1+1 dimensional dilaton gravity implies a catastrophic event at the end point of black hole evaporation. The proof is completely independent of the physics at Planck scales, which suggests that the same will occur in any theory of quantum gravity which only admits trivial space-time topologies.Comment: 8 pages, 3 figures (included), UTTG-32-9

On an unsolved question about the Smarandache Square-Partial-Digital Subsequence

Reporting the solution of an unsolved question on Smarandache Square-Partial-Digital Subsequence. Founding it by extended computer search. Some new questions about palindromic numbers and prime numbers in SSPDS are posed too

Saturn\u27s Rings: What GM\u27s Saturn Project Is Really About

[Excerpt] In their listing of top news stories of 1985 in the economically depressed Youngstown-Warren area, local newspapers consistently listed Saturn mania near the top. In an effort to attract the Saturn project, the local community offered GM a sizable economic development package, organized a 100-car caravan to GM headquarters delivering 200,000 letters from local residents and school children, and bought billboard space and television time in Detroit. This continuation of Saturn mania belies the belief that it was an essentially harmless exercise in corporate public relations. Rather, there is much evidence to suggest that throughout the Saturn campaign GM misled the public about its intention to build an inexpensive small car; diverted public and union attention from its plans for plant closings, technological displacement and the importing of cars from its foreign subsidiaries; forced additional concessions that have weakened the UAW; and shaped the public debate surrounding U.S. economic decline and future economic development

The Revitilization of Organized Labor in Youngstown

[Excerpt] From the Little Steel strikes of the 1930\u27s to the industrial strike at General Motor\u27s Lordstown complex in the early 1970\u27s, organized labor in the Youngstown area has been a force to be reckoned with in its efforts to protect its membership and improve the quality of life of working people. Yet, throughout the late 1960\u27s and 1970\u27s, the labor community increasingly suffered the ill-effects of business unionism. Business unionism\u27s preoccupation with economism and sectionalism caused the local labor movement to narrow its social focus and to become increasingly fragmented, insular and directionless. These inherent weaknesses became painfully obvious as corporate America systematically disinvested in the Youngstown area