摘要:

We present here a cohomological analysis of the new spacetime superalgebras that arise in the context of superbrane theory. They lead to enlarged superspaces that allow us to write D-brane actions in terms of fields associated with the additional superspace variables. This suggests that there is an extended superspace/worldvolume fields democracy for superbranes. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419311

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The physics that is traditionally formulated in one-time-physics (1T-physics) can also be formulated in two-time-physics (2T-physics). The physical phenomena in 1T or 2T physics are not different, but the spacetime formalism used to describe them is. The 2T description involves two extra dimensions (one time and one space), is more symmetric, and makes manifest many hidden features of 1T-physics. One such hidden feature is that families of apparently different 1T-dynamical systems inddimensions holographically describe the same 2T system ind+2dimensions. In 2T-physics there are two timelike dimensions, but there is also a crucial gauge symmetry that thins out spacetime, thus making 2T-physics effectively equivalent to 1T-physics. The gauge symmetry is also responsible for ensuring causality and unitarity in a spacetime with two timelike dimensions. What is gained through 2T-physics is a unification of diverse 1T dynamics by making manifest hidden symmetries and relationships among them. Such relationships is the evidence for the presence of the higher dimensional spacetime structure. 2T-physics could be viewed as a device for gaining a better understanding of 1T-physics, but beyond this, 2T-physics offers new vistas in the search of the unified theory while raising deep questions about the meaning of spacetime. In these lectures, the recent developments in the powerful gauge field theory formulation of 2T-physics will be described after a brief review of the results obtained so far in the more intuitive worldline approach. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419312

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We discuss a generalized form of IIA/IIB supergravity depending onallR-R potentialsC(p)(p=0,1,&ellip;9)as the effective field theory of Type IIA/IIB superstring theory. For the IIA case we explicitly break this R-R democracy to eitherp⩽3orp⩾5which allows us to write a new bulk action that can be coupled toN=1supersymmetric brane actions. The case of 8-branes is studied in detail using the new bulk & brane action. The supersymmetric negative tension branes without matter excitations can be viewed as orientifolds in the effective action. These D8-branes and O8-planes are fundamental in Type I′string theory. A BPS 8-brane solution is given which satisfies the jump conditions on the wall. As an application of our results we derive a quantization of the mass parameter and the cosmological constant in string units. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419313

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

In these two lectures, delivered at the XXXVII Karpacz Winter School, February 2001, I review some applications of superspace in various topics related to string theory and M-theory. The first lecture is mainly devoted to descriptions of brane dynamics formulated in supergravity backgrounds. The second lecture concerns the use of superspace techniques for determining consistent interactions in supersymmetric gauge theory and supergravity,e.g.,&agr;′-corrections from string/M-theory. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419314

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We discuss how supersymmetric Born-Infeld theories can be derived from the concept of partial breaking of global supersymmetry (PBGS). ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419315

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Finite Unified Theories (FUTs) are conventionalN=1supersymmetric Grand Unified Theories, which can be made all-loop finite, both in the dimensionless (gauge and Yukawa couplings) and dimensionful (soft supersymmetry breaking terms) sectors. This remarkable property leads to a drastic reduction in the number of free parameters, which in turn leads to an accurate prediction of the top quark mass in the dimensionless sector, and predictions for the Higgs boson mass and the s-spectrum in the dimensionful sector. Among the characteristics of the latter ones are: 1) The lightest Higgs boson mass is predicted to be in the window 120–130 GeV, in case the LSP is neutralino, while in case the LSP is the&tgr;˜(which can be consistently accommodated in presence of bilinear R-parity violating terms) it can be as light as 111 GeV. 2) The s-spectrum starts above several hundreds of GeV. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419316

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

We construct the explicit form of the four-dimensional effective supergravity action, which describes low-energy physics of the Randall-Sundrum model with moduli fields in the bulk and charged chiral matter living on the branes. The low-energy action is derived from the compactification of a locally supersymmetric model in five dimensions. We deduce a generalization of the effective 4d action to the case of a general, not necessarily exponential, warp factor. The mechanism of supersymmetry breaking mediation is described, which relies on the non-trivial configuration of theZ2-odd bulk fields. Broken supersymmetry leads to stabilization of the interbrane distance. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419317

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Basics of the geometrical formulation of the dynamics of supersymmetric objects are considered and its relation to conventional formulations of superbranes is discussed. In particular, we demonstrate how the kappa-symmetry of the Green–Schwarz formulation shows up from local worldvolume supersymmetry, and briefly discuss applications of the superembedding approach. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419318

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Standard superspace Feynman diagram rules give one estimate of the onset of ultraviolet divergences in supergravity and super Yang-Mills theories. Newer techniques motivated by string theory but which also make essential use of unitarity cutting rules give another in certain cases. We trace the difference to the treatment of higher-dimensional gauge invariance in supersymmetric theories that can be dimensionally oxidized to pure supersymmetric gauge theories. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419319

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Theories in 5 dimensions with minimal supersymmetry are studied for domain-wall solutions and in the context of the AdS/CFT correspondence. The scalar manifold is a product of a very special real manifold and a quaternionic-Ka¨hler manifold. Superconformal methods can clarify the structure of these manifolds, which are part of the family of special manifolds. BPS solutions depending on the scalars and a warp factor of the 5-dimensional metric with a flat 4-dimensional metric can interpolate between critical points determined by algebraic attractor equations. The mixing of vector and hypermultiplets is essential to obtain UV and IR critical points. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1419320

出版商:AIP    

年代:1901

数据来源: AIP