3,969 research outputs found
Class Problem!: Why the Inconsistent Application of Rule 23\u27s Class Certification Requirements During Overbreadth Analysis is a Threat to Litigant Certainty
Rule 23 of the Federal Rules of Civil Procedure is home to the class action device. It is well-documented that this rule significantly impacts our legal system. As a result, the need for its effective utilization has been apparent since its introduction. Despite this, federal courts have inconsistently applied the rule during their analyses of overbroad class definitions at the class certification stage. Consequently, parties involved in such litigation have been exposed to unnecessary costs and the potential for forum shopping. Nonetheless, this judicial inconsistency has gone largely unrecognized because it does not implicate the results of class certification. Hence, courts here must first recognize the general need for uniformity before a precise standard for overbreadth analysis may be chosen. Only then, this Note argues, may the aforementioned detrimental consequences be avoided
Supersymmetry for Gauged Double Field Theory and Generalised Scherk-Schwarz Reductions
Previous constructions of supersymmetry for double field theory have relied
on the so called strong constraint. In this paper, the strong constraint is
relaxed and the theory is shown to possess supersymmetry once the generalised
Scherk-Schwarz reduction is imposed. The equivalence between the generalised
Scherk-Schwarz reduced theory and the gauged double field theory is then
examined in detail for the supersymmetric theory. As a byproduct we write the
generalised Killing spinor equations for the supersymmetric double field
theory.Comment: 29 pages, LateX, v2 typos fixed and some improved discussion, version
as in Journa
The string partition function in Hull's doubled formalism
T-duality is one of the essential elements of string theory. Recently, Hull
has developed a formalism where the dimension of the target space is doubled so
as to make T-duality manifest. This is then supplemented with a constraint
equation that allows the connection to the usual string sigma model. This paper
analyses the partition function of the doubled formalism by interpreting the
constraint equation as that of a chiral scalar and then using holomorphic
factorisation techniques to determine the partition function. We find there is
quantum equivalence to the ordinary string once the topological interaction
term is included.Comment: 16 pages, latex, v2 typos corrected, v3 some comments adde
Branes are Waves and Monopoles
In a recent paper it was shown that fundamental strings are null waves in
Double Field Theory. Similarly, membranes are waves in exceptional extended
geometry. Here the story is continued by showing how various branes are
Kaluza-Klein monopoles of these higher dimensional theories. Examining the
specific case of the E7 exceptional extended geometry, we see that all branes
are both waves and monopoles. Along the way we discuss the O(d; d)
transformation of localized brane solutions not associated to an isometry and
how true T-duality emerges in Double Field Theory when the background possesses
isometries.Comment: 32 pages, Latex, v2, typos correcte
Duality Symmetric String and M-Theory
We review recent developments in duality symmetric string theory. We begin
with the world sheet doubled formalism which describes strings in an extended
space time with extra coordinates conjugate to winding modes. This formalism is
T-duality symmetric and can accommodate non-geometric T-fold backgrounds which
are beyond the scope of Riemannian geometry. Vanishing of the conformal anomaly
of this theory can be interpreted as a set of spacetime equations for the
background fields. These equations follow from an action principle that has
been dubbed Double Field Theory (DFT). We review the aspects of generalised
geometry relevant for DFT. We outline recent extensions of DFT and explain how,
by relaxing the so-called strong constraint with a Scherk Schwarz ansatz, one
can obtain backgrounds that simultaneously depend on both the regular and
T-dual coordinates. This provides a purely geometric higher dimensional origin
to gauged supergravities that arise from non-geometric compactification. We
then turn to M-theory and describe recent progress in formulating an E_{n(n)}
U-duality covariant description of the dynamics. We describe how spacetime may
be extended to accommodate coordinates conjugate to brane wrapping modes and
the construction of generalised metrics in this extend space that unite the
bosonic fields of supergravity into a single object. We review the action
principles for these theories and their novel gauge symmetries. We also
describe how a Scherk Schwarz reduction can be applied in the M-theory context
and the resulting relationship to the embedding tensor formulation of maximal
gauged supergravities.Comment: Review article. 122 pages. V2 Published Version in Physics Report
In Cold Blood: The Vietnam War in Textbooks
An analysis of textbook coverage of the Vietnam War
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