122261153
Generalized Grassmann variables for anyon field theory
Abstract Just as fermion fields have to be represented by anticommuting variables, anyon fields require q -commuting ones. Properties of such variables and their integration rules are discussed here, mainly for the case of semions ( q = ± i ).
9159427
Poincaré invariance of anomalous gauge theories.
We establish the Poincare invariance of anomalous gauge theories in two dimensions, for both the Abelian and non-Abelian cases, in the canonical Hamiltonian formalism. It is shown that, despite the noncovariant appearance of the constraints of these theories, Poincare generators can be constructed which obey the correct algebra and yield the correct transformations in the constrained space.
121982569
MANIFEST AND NON-MANIFEST LORENTZ INVARIANCE FOR GAUGED SELF-DUAL BOSONS
The standard chiral way of gauging self-dual bosons can be described in either a non-manifestly Lorentz invariant formalism or a formalism where auxiliary fields are used to make Lorentz invariance manifest. The two descriptions are shown to be equivalent. The vector way of gauging, which is inconsistent in the second formalism, is shown to break Lorentz invariance in the first. Finally the new chiral way of gauging recently introduced by us in the first formalism is shown to admit a description in the second.
15143825
An improved lower bound on black hole entropy in the quantum geometry approach
The corrected counting of states for black holes in the quantum geometry approach shows that the dominant configurations are distributions of spins that include spins exceeding one-half at the punctures. This alters the value of the Immirzi parameter and the black hole entropy. A framework for the calculation of black hole entropy in the quantum geometry approach was formulated in [1]. In that paper a lower bound for the entropy was worked out on the basis of the association of spin one-half to each puncture and found to be proportional to the area of the horizon. The proportionality constant involves what is known as the Immirzi parameter, which can be chosen so that the entropy becomes a quarter of the area. Recently, this lower bound was sharpened in [2] to include a logarithmic correction − 1 2 lnA. Subsequently, it was pointed out in [3] that the dominant term in the entropy is somewhat higher while the logarithmic correction is unaffected in their calculation. In the present note we investigate the modification of the lower bound of [2] in view of this development. A general configuration has sj punctures with spin j. Note that 2 ∑
119347706
Counting black hole microscopic states in loop quantum gravity
Counting of microscopic states of black holes is performed within the framework of loop quantum gravity. This is the first calculation of the pure horizon states using statistical methods, which reveals the possibility of additional states missed in the earlier calculations, leading to an increase of entropy. Also for the first time a microcanonical temperature is introduced within the framework.
7905729
Quantization of Gauge Theories with Anomalies
In this talk, we briefly review the basic concepts of anomalous gauge theories. It has been known for some time how theories with local anomalies can be handled. Recently it has been pointed out that global anomalies, which obstruct the quantization of certain gauge theories in the temporal gauge, get bypassed in canonical quantization.
42299755
BMS supertranslations and Weinberg’s soft graviton theorem
A bstractRecently it was conjectured that a certain infinite-dimensional “diagonal” subgroup of BMS supertranslations acting on past and future null infinity ( and ) is an exact symmetry of the quantum gravity S-matrix, and an associated Ward identity was derived. In this paper we show that this supertranslation Ward identity is precisely equivalent to Weinberg’s soft graviton theorem. Along the way we construct the canonical generators of supertranslations at , including the relevant soft graviton contributions. Boundary conditions at the past and future of and a correspondingly modified Dirac bracket are required. The soft gravitons enter as boundary modes and are manifestly the Goldstone bosons of spontaneously broken supertranslation invariance.
53655055
New symmetries of massless QED
A bstractAn infinite number of physically nontrivial symmetries are found for abelian gauge theories with massless charged particles. They are generated by large U(1) gauge transformations that asymptotically approach an arbitrary function εzz¯$$ \varepsilon \left(z,\overline{z}\right) $$ on the conformal sphere at future null infinity () but are independent of the retarded time. The value of ε at past null infinity () is determined from that on by the condition that it take the same value at either end of any light ray crossing Minkowski space. The ε ≠ constant symmetries are spontaneously broken in the usual vacuum. The associated Goldstone modes are zero-momentum photons and comprise a U(1) boson living on the conformal sphere. The Ward identity associated with this asymptotic symmetry is shown to be the abelian soft photon theorem.