Effective Action and Measure in Matrix Model of IIB Superstrings

We calculate an effective action and measure induced by the integration over the auxiliary field in the matrix model recently proposed to describe IIB superstrings. It is shown that the measure of integration over the auxiliary matrix is uniquely determined by locality and reparametrization invariance of the resulting effective action. The large--$N$ limit of the induced measure for string coordinates is discussed in detail. It is found to be ultralocal and, thus, possibly is irrelevant in the continuum limit. The model of the GKM type is considered in relation to the effective action problem.Comment: 9pp., Latex; v2: the discussion of the large N limit of the induced measure is substantially expande

British propaganda: Its impact on America in World War I

Psychological warfare, with propaganda as one of its principal instrument, emerged in World War I as a lethal force which in some ways was comparable to technological advances in weaponry. Just as aerial bombing, deadly gases and modern arms marked a new era in whole-sale killing, so propaganda was a milestone in the battle of warring nations to control public opinion. The war did not usher in propaganda; its roots have been traced back to the Crusades and beyond. It was the Great War, however, that produced the beginnings of today\u27s sophisticated propaganda techniques. So effective, in fact, was World War I propaganda that some scholars hold it chiefly responsible for America\u27s decision to take up arms against Germany

FEMALE NONTRADITIONAL STUDENTS IN HIGHER EDUCATION

Thesis (Ph.D.) - Indiana University, School of Education, 2010Current enrollment trends indicate that women now outnumber men in college enrollment among all racial/ethnic populations (National Center for Education Statistics [NCES], 2002b, 2007), and that a large portion of these students are nontraditional (NT). Today, more than 73% of all students in undergraduate institutions are described as different from traditional college students (NCES, 2002b, 2007; St John & Tuttle, 2004; Wylie, 2005). Research on NT students suggests these students are more likely to be female (American Council on Education (ACE), 2004; Corrigan, 2003), a member of an ethnic or racial minority (ACE. 2004), and have limited resources for and knowledge of higher education's institutional practices and expectations. Consequently, they have more difficulty persisting in college (Corrigan, 2003; Pike & Kuh, 2006; Rankin & Reason, 2005). Their early and successful academic and social integration into the college environment is critical as the highest level of attrition occurs during the freshmen year (American College Testing (ACT), 2003; Duggan, 2001; NCES, 2002b; St. John & Tuttle, 2004; Tinto, 2000; Wylie, 2005). This investigation examined obstacles female nontraditional (FNT) students encounter as they enter and transition to college, described how they overcome them, explored background characteristics of those who persist, and looked at the relationship between having a career goal, motivation, and persistence. The qualitative case study focused on multiple cases within a bounded system. The study findings indicate that students who persist establish broad external networks of support, express confidence and goal clarity, increase self-efficacy, develop effective coping strategies, and learn to use institutional support systems. Findings did not support the strong positive influence of having a specific career goal, but did underscore the importance of career value

Direct thrust measurement of a 30-cm ion thruster

A direct thrust measurement of a 30-cm diameter ion thruster was accomplished by means of a laser interferometer thrust stand. The thruster was supported in a pendulum manner by three 3.65-m long wires. Electrical power was provided by means of 18 mercury filled pots. A movable 23-button planar probe rake was used to determine thrust loss due to ion beam divergence. Values of thrust, thrust loss due to ion beam divergence, and thrust loss due to multiple ionization were measured for ion beam currents ranging from 0.5 A to 2.5 A. Measured thrust values indicate an accuracy of approximately 1% and are in good agreement with thrust values calculated by indirect measurements

More Superstrings from Supergravity

The four six-dimensional ``little string'' theories are all described in the infinite momentum frame (IMF) as matrix theories by non-trivial 1+1 dimensional infra-red fixed points. We characterize these fixed points using supergravity. Starting from the matrix theory definition of M5-branes, we derive an associated dual supergravity description of the fixed point theories, arising as the near horizon geometry of certain brane configurations. These supergravity solutions are all smooth, and involve three dimensional Anti-de Sitter space AdS_3. They therefore provide a complete description of the fixed point theories, and hence the IMF little string theories, if the AdS/CFT correspondence holds.Comment: 17 pages, harvmac.tex; epsf.tex for two decorative figures (References added.

Ultrarelativistic boost of spinning black rings

We study the D=5 Emparan-Reall spinning black ring under an ultrarelativistic boost along an arbitrary direction. We analytically determine the resulting shock pp-wave, in particular for boosts along axes orthogonal and parallel to the plane of rotation. The solution becomes physically more interesting and simpler if one enforces equilibrium between the forces on the ring. We also comment on the ultrarelativistic limit of recently found supersymmetric black rings with two independent angular momenta. Essential distinct features with respect to the boosted Myers-Perry black holes are pointed out.Comment: 15 pages, 2 figures. v2: added multipole expansions at spatial infinity, and a comparison with the boosted Myers-Perry solution in a new appendix. To appear in JHE

Black Holes of a Minimal Size in String Gravity

A lower limit for a neutral black hole size is obtained in the frames of the string gravity model with the second order curvature correction. It is shown that this effect remains when the third order curvature correction is also taken into account and argued that such restriction does exist in all perturbative orders of curvature expansions.Comment: 6 LaTeX pages, 1 PostScript figure (epsfig.sty), minor changes in the text and references, submitted to Int.J.Mod.Phy

Tunnelling Effects in a Brane System and Quantum Hall Physics

We argue that a system of interacting D-branes, generalizing a recent proposal, can be modelled as a Quantum Hall fluid. We show that tachyon condensation in such a system is equivalent to one particle tunnelling. In a conformal field theory effective description, that induces a transition from a theory with central charge c=2 to a theory with c=3/2, with a corresponding symmetry enhancement.Comment: 12 pages, no figures, Latex, some aspects clarified, sect.3 expanded, references adde

Ten Dimensional Black Hole and the D0-brane Threshold Bound State

We discuss the ten dimensional black holes made of D0-branes in the regime where the effective coupling is large, and yet the 11D geometry is unimportant. We suggest that these black holes can be interpreted as excitations over the threshold bound state. Thus, the entropy formula for the former is used to predict a scaling region of the wave function of the latter. The horizon radius and the mass gap predicted in this picture agree with the formulas derived from the classical geometry.Comment: 11 pages, harvmac; v2: typos corrected, argument for the convergence of two integrals improved, v3: one ref. adde