55 research outputs found
Electrocardiography monitoring system and method
Systems and methods for electrocardiography monitoring use multiple capacitive sensors in order to determine reliable measurements of electrophysiological information of a patient. Relative coupling strength and/or reliability is used to select dynamically which sensors to use in order to determine, in particular, an electrocardiogram of the patient.</p
Chaotic Coupling Constants
We examine some novel physical consequences of the general structure of
moduli spaces of string vacua. These include (1) finiteness of the volume of
the moduli space and (2) chaotic motion of the moduli in the early universe. To
fix ideas we examine in detail the example of the (conjectural) dilaton-axion
``-duality'' of four-dimensional string compactifications. The facts (1) and
(2) together might help to solve some problems with the standard scenarios for
supersymmetry breaking and vacuum selection in string theory.Comment: 18 pages (4 figs), YCTP-P2-94, RU-94-2
Duality Anomaly Cancellation, Minimal String Unification and the Effective Low-Energy Lagrangian of 4-D Strings
We present a systematic study of the constraints coming from target-space
duality and the associated duality anomaly cancellations on orbifold-like 4-D
strings. A prominent role is played by the modular weights of the massless
fields. We present a general classification of all possible modular weights of
massless fields in Abelian orbifolds. We show that the cancellation of modular
anomalies strongly constrains the massless fermion content of the theory, in
close analogy with the standard ABJ anomalies. We emphasize the validity of
this approach not only for (2,2) orbifolds but for (0,2) models with and
without Wilson lines. As an application one can show that one cannot build a
or orbifold whose massless charged sector with respect
to the (level one) gauge group is that of the
minimal supersymmetric standard model, since any such model would necessarily
have duality anomalies. A general study of those constraints for Abelian
orbifolds is presented. Duality anomalies are also related to the computation
of string threshold corrections to gauge coupling constants. We present an
analysis of the possible relevance of those threshold corrections to the
computation of and for all Abelian orbifolds. Some
particular {\it minimal} scenarios, namely those based on all
orbifolds except Comment: 69 page
Threshold Corrections and Symmetry Enhancement in String Compactifications
We present the computation of threshold functions for Abelian orbifold
compactifications. Specifically, starting from the massive, moduli-dependent
string spectrum after compactification, we derive the threshold functions as
target space duality invariant free energies (sum over massive string states).
In particular we work out the dependence on the continuous Wilson line moduli
fields. In addition we concentrate on the physically interesting effect that at
certain critical points in the orbifold moduli spaces additional massless
states appear in the string spectrum leading to logarithmic singularities in
the threshold functions. We discuss this effect for the gauge coupling
threshold corrections; here the appearance of additional massless states is
directly related to the Higgs effect in string theory. In addition the
singularities in the threshold functions are relevant for the loop corrections
to the gravitational coupling constants.Comment: 68 pages (equations 8.16 and 8.17 corrected; added footnotes 4,5,11
Duality in String Theory
In this lecture we review some of the recent developments in string theory on
an introductory and qualitative level. In particular we focus on S-T-U
dualities of toroidally compactified ten-dimensional string theories and
outline the connection to M-theory. Dualities among string vacua with less
supersymmetries in six and four space-time dimensions is discussed and the
concept of F-theory is briefly presented. (Lecture given by J. Louis at the
Workshop on Gauge Theories, Applied Supersymmetry and Quantum Gravity, Imperial
College, London, UK, July 5--10, 1996.)Comment: 38 pages, Latex, 2 figure
Holomorphic Couplings in String Theory
In these lectures we review the properties of holomorphic couplings in the
effective action of four-dimensional N=1 and N=2 closed string vacua. We
briefly outline their role in establishing a duality among (classes of)
different string vacua. (Lectures presented by J. Louis at the Trieste Spring
School 1996.)Comment: 32 pages, Late
The twilight of the Liberal Social Contract? On the Reception of Rawlsian Political Liberalism
This chapter discusses the Rawlsian project of public reason, or public justification-based 'political' liberalism, and its reception. After a brief philosophical rather than philological reconstruction of the project, the chapter revolves around a distinction between idealist and realist responses to it. Focusing on political liberalism’s critical reception illuminates an overarching question: was Rawls’s revival of a contractualist approach to liberal legitimacy a fruitful move for liberalism and/or the social contract tradition? The last section contains a largely negative answer to that question. Nonetheless the chapter's conclusion shows that the research programme of political liberalism provided and continues to provide illuminating insights into the limitations of liberal contractualism, especially under conditions of persistent and radical diversity. The programme is, however, less receptive to challenges to do with the relative decline of the power of modern states
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