scholarly journals 3+1DMassless Weyl Spinors from Bosonic Scalar-Tensor Duality

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Amoretti ◽  
Alessandro Braggio ◽  
Giacomo Caruso ◽  
Nicola Maggiore ◽  
Nicodemo Magnoli
Keyword(s):  
Dirac Equation ◽  
Charge Density ◽  
Dimensional Reduction ◽  
Degrees Of Freedom ◽  
Planar Boundary ◽  
Weyl Spinor ◽  
Bf Theory ◽  
Free Theory ◽  
Tomographic Representation

We consider the fermionization of a bosonic-free theory characterized by the3+1Dscalar-tensor duality. This duality can be interpreted as the dimensional reduction, via a planar boundary, of the4+1Dtopological BF theory. In this model, adopting the Sommerfield tomographic representation of quantized bosonic fields, we explicitly build a fermionic operator and its associated Klein factor such that it satisfies the correct anticommutation relations. Interestingly, we demonstrate that this operator satisfies the massless Dirac equation and that it can be identified with a3+1DWeyl spinor. Finally, as an explicit example, we write the integrated charge density in terms of the tomographic transformed bosonic degrees of freedom.

scholarly journals Topologically Protected Duality on The Boundary of Maxwell-BF Theory

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 921 ◽  
Author(s):  
Alberto Blasi ◽  
Nicola Maggiore
Keyword(s):  
Degrees Of Freedom ◽  
Three Dimensional ◽  
General Boundary Conditions ◽  
Planar Boundary ◽  
Dimensional Theory ◽  
Electromagnetic Structure ◽  
Bf Theory ◽  
Gauge Symmetries ◽  
Dimensional Spacetime

The Maxwell-BF theory with a single-sided planar boundary is considered in Euclidean four-dimensional spacetime. The presence of a boundary breaks the Ward identities, which describe the gauge symmetries of the theory, and, using standard methods of quantum field theory, the most general boundary conditions and a nontrivial current algebra on the boundary are derived. The electromagnetic structure, which characterizes the boundary, is used to identify the three-dimensional degrees of freedom, which turn out to be formed by a scalar field and a vector field, related by a duality relation. The induced three-dimensional theory shows a strong–weak coupling duality, which separates different regimes described by different covariant actions. The role of the Maxwell term in the bulk action is discussed, together with the relevance of the topological nature of the bulk action for the boundary physics.

scholarly journals The statistical mechanics of near-extremal black holes

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Luca V. Iliesiu ◽  
Gustavo J. Turiaci
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Partition Function ◽  
Gauge Field ◽  
Dimensional Reduction ◽  
Degrees Of Freedom ◽  
Energy Scale ◽  
Fixed Charge ◽  
Extremal Black Hole ◽  
Extremal Black Holes

Abstract An important open question in black hole thermodynamics is about the existence of a “mass gap” between an extremal black hole and the lightest near-extremal state within a sector of fixed charge. In this paper, we reliably compute the partition function of Reissner-Nordström near-extremal black holes at temperature scales comparable to the conjectured gap. We find that the density of states at fixed charge does not exhibit a gap; rather, at the expected gap energy scale, we see a continuum of states. We compute the partition function in the canonical and grand canonical ensembles, keeping track of all the fields appearing through a dimensional reduction on S2 in the near-horizon region. Our calculation shows that the relevant degrees of freedom at low temperatures are those of 2d Jackiw-Teitelboim gravity coupled to the electromagnetic U(1) gauge field and to an SO(3) gauge field generated by the dimensional reduction.

scholarly journals Electret formation in transition metal oxides by electrochemical amorphization

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Yong-Jin Kim ◽  
Chan-Ho Yang
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Charge Density ◽  
Electric Fields ◽  
Transition Metal Oxides ◽  
Degrees Of Freedom ◽  
Permanent Magnets ◽  
Underlying Mechanism ◽  
Diffusion Reaction ◽  
Wide Range

AbstractTransition metal oxides (TMOs) are an important class of materials that show a wide range of functionalities involving spin, charge, and lattice degrees of freedom. The strong correlation between electrons in d-orbitals and the multivalence nature give rise to a variety of exotic electronic states ranging from insulator to superconductor and cause intriguing phase competition phenomena. Despite a burst of research on the multifarious functionalities in TMOs, little attention has been paid to the formation and integration of an electret—a type of quasi-permanent electric field generator useful for nanoscale functional devices as an electric counterpart to permanent magnets. Here, we find that an electret can be created in LaMnO3 thin films by tip-induced electric fields, with a considerable surface height change, via solid-state electrochemical amorphization. The surface charge density of the formed electret area reaches ~400 nC cm−2 and persists without significant charge reduction for more than a year. The temporal evolution of the surface height, charge density, and electric potential are systematically examined by scanning probe microscopy. The underlying mechanism is theoretically analyzed based on a drift-diffusion-reaction model, suggesting that positively charged particles, which are likely protons produced by the dissociation of water, play crucial roles as trapped charges and a catalysis to trigger amorphization. Our finding opens a new horizon for multifunctional TMOs.

scholarly journals Dirac equation based on the vector representation of the Lorentz group

2020 ◽  
Vol 135 (10) ◽  
Author(s):  
Eckart Marsch ◽  
Yasuhito Narita
Keyword(s):  
Gauge Theory ◽  
Dirac Equation ◽  
Lorentz Group ◽  
Degrees Of Freedom ◽  
Lagrangian Density ◽  
Degree Of Freedom ◽  
Vector Representation ◽  
Massive Fermion

AbstractIn this paper, we derive an expanded Dirac equation for a massive fermion doublet, which has in addition to the particle/antiparticle and spin-up/spin-down degrees of freedom explicity an isospin-type degree of freedom. We begin with revisiting the four-vector Lorentz group generators, define the corresponding gamma matrices and then write a Dirac equation for the fermion doublet with eight spinor components. The appropriate Lagrangian density is established, and the related chiral and SU(2) symmetry is discussed in detail, as well as applications to an electroweak-style gauge theory. In “Appendix,” we present some of the relevant matrices.

scholarly journals Multiple choice of gauge generators and consistency of interactions

2014 ◽  
Vol 29 (31) ◽  
pp. 1450167 ◽  
Author(s):  
S. L. Lyakhovich ◽  
A. A. Sharapov
Keyword(s):  
Gauge Symmetry ◽  
Simple Model ◽  
Degrees Of Freedom ◽  
Multiple Choice ◽  
Gravity Models ◽  
Coupling Constant ◽  
Free Theory ◽  
Gauge Symmetries

It is usually assumed that any consistent interaction either deforms or retains the gauge symmetries of the corresponding free theory. We propose a simple model where an obvious irreducible gauge symmetry does not survive an interaction, while the interaction is consistent as it preserves the number of physical degrees of freedom. The model turns out admitting a less obvious reducible set of gauge generators which is compatible with the interaction and smooth in coupling constant. Possible application to gravity models is discussed.

scholarly journals ELECTROMAGNETIC DUALITY ON THE LIGHT-FRONT IN THE PRESENCE OF EXTERNAL SOURCES

2000 ◽  
Vol 15 (30) ◽  
pp. 4739-4748 ◽  
Author(s):  
ASMITA MUKHERJEE ◽  
SOMDATTA BHATTACHARYA
Keyword(s):  
Degrees Of Freedom ◽  
Transverse Field ◽  
Light Front ◽  
Duality Transformation ◽  
Hamiltonian Density ◽  
Free Theory ◽  
External Sources ◽  
Normal Light ◽  
The Right ◽  
Dynamical Field

We investigate the issue of electromagnetic duality on the light-front. We work with Zwanziger's theory of electric and magnetic sources which is appropriate for treating duality. When quantized on the light-front in the light-front gauge, this theory yields two independent phase space degrees of freedom, namely the two transverse field components, the right number to describe the gauge field sector of normal light-front QED and also the appropriate commutator between them. The electromagnetic duality transformation formulated in terms of them is similar in form to the Susskind transformation proposed for the free theory, provided one identifies them as the dynamical field components of the photon on the light-front in the presence of magnetic sources. The Hamiltonian density written in terms of these components is invariant under the duality transformation.

scholarly journals Consistent Interactions in Terms of the Generalized Fields Method

1997 ◽  
Vol 12 (24) ◽  
pp. 4387-4397 ◽  
Author(s):  
Ömer F. Dayi
Keyword(s):  
Master Equation ◽  
Gauge Field ◽  
Tensor Field ◽  
General Scheme ◽  
Antisymmetric Tensor ◽  
Four Dimensions ◽  
Bf Theory ◽  
Free Theory ◽  
Antisymmetric Tensor Field

The interactions which preserve the structure of the gauge interactions of the free theory are introduced in terms of the generalized fields method for solving the Batalin–Vilkovisky master equation. It is shown that by virtue of this method the solution of the descent equations resulting from the cohomological analysis is provided straightforwardly. The general scheme is illustrated by applying it to the spin 1 gauge field in three and four dimensions, to free BF theory in 2D, and to the antisymmetric tensor field in any dimension. It is shown that it reproduces the results obtained by cohomological techniques.

scholarly journals Relativistic currents on ideal Aharonov–Bohm cylinders

2016 ◽  
Vol 30 (26) ◽  
pp. 1650190 ◽  
Author(s):  
Ion I. Cotăescu ◽  
Doru-Marcel S. Băltăţeanu ◽  
Ion I. Cotăescu
Keyword(s):  
Angular Momentum ◽  
Dirac Equation ◽  
Relativistic Theory ◽  
Degrees Of Freedom ◽  
Total Angular Momentum ◽  
Relativistic Effect ◽  
Dirac Fermions ◽  
Persistent Currents ◽  
Relativistic Approach ◽  
Aharonov Bohm

The relativistic theory of the Dirac fermions moving on cylinders in external Aharonov–Bohm (AB) field is built starting with a suitably restricted Dirac equation whose spin degrees of freedom are not affected. The exact solutions of this equation on finite or infinite AB cylinders allow one to derive the relativistic circular and longitudinal currents pointing out their principal features. It is shown that all the circular currents are related to the energy in the same manner on cylinders or rings either in the relativistic approach or in the nonrelativistic one. The specific relativistic effect is the saturation of the circular currents for high values of the total angular momentum. Based on this property some approximative closed formulas are deduced for the total persistent current at [Formula: see text] on finite AB cylinders. Moreover, it is shown that all the persistent currents on finite cylinders or rings have similar nonrelativistic limits.

scholarly journals Coherent Phonon Disruption and Lock-In During a Photoinduced Charge-Density-Wave Phase Transition

2021 ◽  
Author(s):  
Spencer A. Reisbick ◽  
Yichao Zhang ◽  
Jialiang Chen ◽  
Paige Engen ◽  
David Flannigan
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Degrees Of Freedom ◽  
Structural Phase ◽  
Density Wave ◽  
Optical Excitation ◽  
Partial Coherence ◽  
Periodic Lattice ◽  
Coherent Phonon ◽  
Quantum Materials

Ultrafast manipulation of phases and phase domains in quantum materials is a key approach to unraveling and harnessing interwoven effects of charge and lattice degrees of freedom. In the intensely-studied charge-density-wave (CDW) material, 1<i>T</i>-TaS<sub>2</sub>, phonon coupling to periodic lattice distortions (PLDs) and atomically-incoherent picosecond structural phase transitions suggest transitional periods could exist for delayed onset of mode coherence. Here we find evidence for such a connection between displacively-excited coherent acoustic phonons and PLDs using 4D ultrafast electron microscopy. Following femtosecond optical excitation of an ultrathin crystal, a propagating hybridized mode is imaged emerging from linear defects within a 1-μm region. Partial coherence and low amplitudes during onset of the incommensurate phase convert to higher-amplitude, increasingly-coherent oscillations as phase-growth stabilizes. The hybrid mode consists of large out-of-plane distortions coupled to basal-plane bond oscillations propagating at anomalously high velocities. The strongly-correlated behaviors observed here represent a potential means to control phase behaviors in quantum materials using defect-engineered coherent-phonon seeding.

scholarly journals Duality and dimensional reduction of 5D BF theory

2013 ◽  
Vol 73 (6) ◽  
Author(s):  
A. Amoretti ◽  
A. Blasi ◽  
G. Caruso ◽  
N. Maggiore ◽  
N. Magnoli
Keyword(s):  
Dimensional Reduction ◽  
Bf Theory
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