1,720,996 research outputs found
Supersymmetry of the three-dimensional Einstein-Hilbert gravity in the Landau gauge
No full textIn analogy with the Chern-Simons action in the Landau gauge, we find for the 3D Einstein-Hilbert gravity an extra symmetry whose Ward operator, together with the linearized Slavnov operator, gives rise to a N=1 supersymmetric algebra. We discuss furthermore the inclusion in the action either of a cosmological constant or of a topological term which permits the exploitation of the tight analogy of 3D gravity with the Chern-Simons models built on complex gauge groups
Supersymmetric structure of four-dimensional antisymmetric tensor fields
No full textAntisymmetric tensor fields are discussed. The model, as other
topological field theories, possesses a supersymmetric off-shell
structure which can be used to define a class of Slavnov invariant
observables
Quasi-topological fractons: a 3D dipolar gauge theory
No full textWe consider the theory of a generic rank-2 tensor field in three spacetime dimensions, which involves a symmetric tensor field transforming under infinitesimal diffeomorphisms, and a vector field, whose gauge transformation depends on a local vector parameter. The gauge fixing shows a non-trivial structure, and some non-intuitive possibilities are listed. Despite the fact that the theory is not topological, the energy-momentum tensor vanishes on-shell, which justifies the "quasi-topological" appellation we give to this theory. We show that the theory has three degrees of freedom. Moreover, we find an interesting physical interpretation, which consists in a generalized planar electromagnetism and in the emergence of two vector charges with restricted mobility. These are typical fractonic behaviours which can be related to the so-called traceless scalar and vector charge theories
Holographic Projection of Electromagnetic Maxwell Theory
No full textThe 4D Maxwell theory with single-sided planar boundary is considered. As a consequence of the presence of the boundary, two broken Ward identities are recovered, which, on-shell, give rise to two conserved currents living on the edge. A Kaç-Moody algebra formed by a subset of the bulk fields is obtained with central charge proportional to the inverse of the Maxwell coupling constant, and the degrees of freedom of the boundary theory are identified as two vector fields, also suggesting that the 3D theory should be a gauge theory. Finally the holographic contact between bulk and boundary theory is reached in two inequivalent ways, both leading to a unique 3D action describing a new gauge theory of two coupled vector fields with a topological Chern-Simons term with massive coefficient. In order to check that the 3D projection of 4D Maxwell theory is well defined, we computed the energy-momentum tensor and the propagators. The role of discrete symmetries is briefly discussed
On the Beta Function in Supersymmetric Gauge Theories
No full textWe re-examine perturbative and nonperturbative aspects of the beta function
in N=1 and N=2 supersymmetric gauge theories, make comments on the recent
literature on the subject and discuss the exactness of several known results
such as the NSVZ beta function
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A note on harmonic gauge(s) in massive gravity
Full text linkWe consider the harmonic gauge condition in linearized gravity, seen as a gauge theory for a symmetric tensor field. Once the harmonic gauge condition is implemented, as customary, according to the Faddeev-Popov procedure, the gauge fixed action still depends on one gauge parameter. Consequently, the harmonic gauge appears to be a class of conditions, rather than a particular one. This allows to give a physical motivation for the covariant harmonic gauge(s), which emerges when the gravitational perturbation is given a mass term. In fact, for a particular choice of harmonic gauge, we find a theory of linearized massive gravity displaying five degrees of freedom, as it should, and which is not affected by the vDVZ discontinuity, differently from what happens in the standard Fierz-Pauli theory
Protected operators in Nu=2, 4 supersymmetric theories
No full textThe anomalous dimension of single and multi-trace composite operators of scalar fields is shown to vanish at all orders of the perturbative series. The proof hold for theories with N =2 supersymmetry with any number of hypermultiplets in a generic representation of the gauge group. It then applies to the finite N =4 theory as well as to nonconformal N =2 models
Gauging Fractons and Linearized Gravity
No full textWe consider the covariant gauge field theory of fractons, which describes a new type of quasiparticles exhibiting novel and non-trivial properties. In particular, we focus on the field theoretical peculiarities which characterize this theory, starting from the fact that, if we accept the paradigm that quantum field theories are defined by their symmetries, fractons unavoidably come together with linearized gravity. The standard Faddeev-Popov procedure to gauge fix the theory leads to a scalar gauge condition, which has two important drawbacks: it is frozen in the Landau gauge and linearized gravity cannot be obtained as a limit. In this paper, we adopt a tensorially alternative gauge fixing, which avoids both problems. In particular, this allows to show that important physical features, such as counting of the degrees of freedom, do not depend on a particular gauge choice, as expected. Moreover, the resulting gauge fixed theory contains both fractons and linearized gravity as a limit, differently from the standard scalar choice
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