摘要:

AbstractWe present the (algebra) group contraction chainSU(1, 1) →P(1, 1) →G(1, 1), whereP(1, 1) andG(1, 1) are the Poincaré and the Galilei groups, respectively, in (1 + 1) dimensions. We have paid attention to the contraction of the pseudo‐extended Poincaré group to the central extended Galilei group. Objects like group laws, coadjoint orbits and representations of the contracted groups have been obtained in terms of their noncontracted counterparts. As an application we study the Moyal quantization of classical systems, having those groups as symmetry groups, by means of the contraction of the so called Stratonovich‐Weyl kernels which provide such qua

ISSN:0015-8208    

DOI:10.1002/prop.2190450202

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractAs a motivation, we first recall the possible connection of electric‐magnetic duality to finiteness inN= 1 super‐Yang‐Mills theories (SYM). Then, we present the criterion for all‐order finiteness (i.e., vanishing of the β‐functions at all orders) inN= 1 SYM. Finally, we apply this finiteness criterion to anSU(5) SGUT. The latter turns out to be all‐order finite if one imposes additiona

ISSN:0015-8208    

DOI:10.1002/prop.2190450203

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractAs an aid to understanding thedisplacement operatordefinition of squeezed states for arbitrary systems, we investigate the properties of systems where there is a Holstein‐Primakoff or Bogoliubov transformation. In these cases theladder‐operator or minimum‐uncertaintydefinitions of squeezed states are equivalent to an extent displacement‐operator definition. We exemplify this in a setting where there are operators satisfying [A, Aå] = 1, but theA's are not necessarily the Fock spacea's; the multiboson system. It has been previously observed that the ground state of a system often can be shown to to be a coherent state. We demonstrate why this must be so. We close with a discussion of an alternative, effective definition of displacement‐operator squee

ISSN:0015-8208    

DOI:10.1002/prop.2190450204

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

ISSN:0015-8208    

DOI:10.1002/prop.2190450201

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY