On Relativistic Brane Probes in Singular Spacetimes

We study the relativistic dynamics of brane probes in singular warped spacetimes and establish limits for such analysis. The behavior of the semiclassical brane probe wave functions implies that unitarity boundary conditions can be imposed at the singularity.Comment: 9 pages, 1 figure, typos corrected and references adde

Exponential Hierarchy From Spacetime Variable String Vacua

It is shown that non-supersymmetric spacetime varying string vacua can lead to an exponential hierarchy between the electroweak and the gravitational scales. The hierarchy is naturally generated by a string coupling of O(1).Comment: 22 pages, Latex, 2 figure

Wave Functionals, Hamiltonians and Renormalization Group

We analyze the renormalization of wave functionals and energy eigenvalues in field theory. A discussion of the structure of the renormalization group equation for a general Hamiltonian system is also given.Comment: 14, CCNY-HEP 5/9

Probing Naked Singularities in Non-supersymmetric String Vacua

We present a detailed analysis of non-supersymmetric spacetime varying string vacua which can lead to an exponential hierarchy between the electroweak and the gravitational scales. In particular, we identify a limit in which these vacua can be interpreted as supersymmetric vacua of F-theory. Furthermore, we study the properties of these solutions as seen by $D7$-brane probes and establish a non-supersymmetric analogue of the enhancon mechanism.Comment: 46 pages, Latex, 7 figures; the brane probe analysis (sections 3 and 4) has been revised, references added and typos correcte

Spin and Rotations in Galois Field Quantum Mechanics

We discuss the properties of Galois Field Quantum Mechanics constructed on a vector space over the finite Galois field GF(q). In particular, we look at 2-level systems analogous to spin, and discuss how SO(3) rotations could be embodied in such a system. We also consider two-particle `spin' correlations and show that the Clauser-Horne-Shimony-Holt (CHSH) inequality is nonetheless not violated in this model.Comment: 21 pages, 11 pdf figures, LaTeX. Uses iopart.cls. Revised introduction. Additional reference

A Note on Effective Lagrangians in Matrix Theory

We study the relation between the effective Lagrangian in Matrix Theory and eleven dimensional supergravity. In particular, we provide a relationship between supergravity operators and the corresponding terms in the post-Newtonian approximation of Matrix Theory.Comment: 7 pages, use harvmac. References adde

On the Nonperturbative Consistency of d=2d=2 String Theory

An infinite number of distinct $d=1$ matrix models reproduce the perturbation theory of $d=2$ string theory. Due to constraints of causality, however, we argue that none of the existing constructions gives a consistent nonperturbative definition of the $d=2$ string.Comment: 10 pages, 2 figures, LaTeX (author's name added

Spacetime Emergence and General Covariance Transmutation

Spacetime emergence refers to the notion that classical spacetime "emerges" as an approximate macroscopic entity from a non-spatio-temporal structure present in a more complete theory of interacting fundamental constituents. In this article, we propose a novel mechanism involving the "soldering" of internal and external spaces for the emergence of spacetime and the twin transmutation of general covariance. In the context of string theory, this mechanism points to a critical four dimensional spacetime background.Comment: 11 pages, v2: version to appear in MPL

Concomitant multiple anomalies of renal vessels and collecting system

Although anomalies of renal vessels and collecting system are relatively frequent, their concomitant occurrence is a rare event. During dissection of a 75-year-old male formalin-embalmed cadaver, we found multiple variations in the renal vessels and renal collecting system. Both kidneys were normal in size and anteriorly malrotated, with duplex collecting system and duplex ureter. One ureter drained the upper part of the kidney and the second ureter drained the lower part of the kidney. Superior and inferior collecting systems were separated by renal parenchyma. The right kidney had two renal arteries, the first renal artery (main renal artery) originating from the abdominal aorta, passing behind the inferior vena cava (IVC) and entering the kidney through the superior and inferior renal hilum. The second artery was the inferior polar artery. In addition, the right kidney had two renal veins as well. Three renal tributaries emerged from the upper and lower portion of the right renal hilum, and they joined to form the main renal vein which drained into the IVC. The lower renal vein was the inferior polar vein. The left kidney had four renal arteries (two hilar arteries and two polar arteries). The main left renal vein emerged from both superior and inferior left renal hilum, passed in front of the abdominal aorta and drained into the IVC. The left kidney also had the inferior polar vein which was divided behind the aorta (retro aortic vein) into two venous trunks. These venous trunks drained separately into posteromedialaspect of the IVC. Finally, the right testicular vein was formed by two tributaries and drained into the IVC, whereas the two left testicular veins drained separately into the left main renal vein