Binary Cosmic Strings

The properties of cosmic strings have been investigated in detail for their implications in early-universe cosmology. Although many variations of the basic structure have been discovered, with implications for both the microscopic and macroscopic properties of cosmic strings, the cylindrical symmetry of the short-distance structure of the string is generally unaffected. In this paper we describe some mechanisms leading to an asymmetric structure of the string core, giving the defects a quasi-two-dimensional character. We also begin to investigate the consequences of this internal structure for the microscopic and macroscopic physics.Comment: 19 pages; uses harvmac (not included

Morita equivalence and T-duality (or B versus Θ\Theta)

T-duality in M(atrix) theory has been argued to be realized as Morita equivalence in Yang-Mills theory on a non-commutative torus (NCSYM). Even though the two have the same structure group, they differ in their action since Morita equivalence makes crucial use of an additional modulus on the NCSYM side, the constant Abelian magnetic background. In this paper, we reanalyze and clarify the correspondence between M(atrix) theory and NCSYM, and provide two resolutions of this puzzle. In the first of them, the standard map is kept and the extra modulus is ignored, but the anomalous transformation is offset by the M(atrix) theory ``rest term''. In the second, the standard map is modified so that the duality transformations agree, and a $SO(d)$ symmetry is found to eliminate the spurious modulus. We argue that this is a true symmetry of supersymmetric Born-Infeld theory on a non-commutative torus, which allows to freely trade a constant magnetic background for non-commutativity of the base-space. We also obtain a BPS mass formula for this theory, invariant under T-duality, U-duality, and continuous $SO(d)$ symmetry.Comment: 15 pages, latex2e, JHEP class; ; v2: minor typos corrected, 2 refs added, note added in proof on relation with SW; final version to appear in JHE

Supersymmetry Constraints on Type IIB Supergravity

Supersymmetry is used to derive conditions on higher derivative terms in the effective action of type IIB supergravity. Using these conditions, we are able to prove earlier conjectures that certain modular invariant interactions of order alpha' **3 relative to the Einstein-Hilbert term are proportional to eigenfunctions of the Laplace operator on the fundamental domain of SL(2,Z). We also discuss how these arguments generalize to terms of higher order in alpha', as well as to compactifications of supergravity.Comment: 31 pages, harvmac (b); minor correction

National Time Accounting: The Currency of Life

This monograph proposes a new approach for measuring features of society’s subjective well-being, based on time allocation and affective experience. We call this approach National Time Accounting (NTA). National Time Accounting is a set of methods for measuring, comparing and analyzing how people spend and experience their time -- across countries, over historical time, or between groups of people within a country at a given time. The approach is based on evaluated time use, or the flow of emotional experience during daily activities. After reviewing evidence on the validity of subjective well-being measures, we present and evaluate diary-based survey techniques designed to measure individuals’ emotional experiences and time use. We illustrate NTA with: (1) a new cross-sectional survey on time use and emotional experience for a representative sample of 4,000 Americans; (2) historical data on the amount of time devoted to various activities in the United States since 1965; and (3) a comparison of time use and wellbeing in the United States and France. In our applications, we focus mainly on the Uindex, a measure of the percentage of time that people spend in an unpleasant state, defined as an instance in which the most intense emotion is a negative one. The U-index helps to overcome some of the limitations of interpersonal comparisons of subjective well-being. National Time Accounting strikes us as a fertile area for future research because of advances in subjective measurement and because time use data are now regularly collected in many countries.

Gauge-fixing, semiclassical approximation and potentials for graded Chern-Simons theories

We perform the Batalin-Vilkovisky analysis of gauge-fixing for graded Chern-Simons theories. Upon constructing an appropriate gauge-fixing fermion, we implement a Landau-type constraint, finding a simple form of the gauge-fixed action. This allows us to extract the associated Feynman rules taking into account the role of ghosts and antighosts. Our gauge-fixing procedure allows for zero-modes, hence is not limited to the acyclic case. We also discuss the semiclassical approximation and the effective potential for massless modes, thereby justifying some of our previous constructions in the Batalin-Vilkovisky approach.Comment: 46 pages, 4 figure

Discovery of Non-radial pulsations in PQ Andromedae

We have detected pulsations in time-series photometry of the WZ Sge dwarf nova PQ And. The strongest peak in the power spectrum occurs at a period of 10.5 minutes. Similar periods have been observed in other WZ Sge systems and are attributed to ZZ Ceti type non-radial pulsations. There is no indication in the photometry of an approximately 1.7 hour orbital period as reported in previous spectroscopic observations.Comment: 7 pages, 5 figure

Stability and secondary resonances in the spatial restricted three-body problem for small mass ratios

This paper is devoted to the study of secondary resonances and the stability of the Lagrangian point L-4 in the spatial restricted three-body problem for moderate mass ratios mu, meaning that mu <= 0.0045. However, we concentrated our investigations on small mass ratios mu <= 0.001, which represent the mass ratios for stable configurations of tadpole orbits in the Solar system. The stability is investigated by numerical methods, computing stability maps in different parameter planes. We started investigating the mass of the secondary: from Earth-mass bodies up to Jupiter-mass bodies. In addition, we changed the orbital elements (eccentricity and inclination) of the secondary and Trojan body. For this parameter space, we found high-order secondary resonances, which are present for various inclinations. To determine secondary resonances we used Rabe's equation and the frequency analysis. In addition, we investigated the stability in and around these secondary resonances