scholarly journals Singularity-free spinors in gravity with propagating torsion

2017 ◽  
Vol 32 (40) ◽  
pp. 1750221 ◽  
Author(s):  
Luca Fabbri
Keyword(s):  
Vector Field ◽  
Axial Vector ◽  
Einstein Gravity ◽  
Matter Distribution ◽  
Renormalizable Theory ◽  
Dirac Matter

We consider the most general renormalizable theory of propagating torsion in Einstein gravity for the Dirac matter distribution and we demonstrate that in this case, torsion is a massive axial-vector field whose coupling to the spinor gives rise to conditions in terms of which gravitational singularities are not bound to form; we discuss how our results improve those that are presented in the existing literature, and that no further improvement can be achieved unless one is ready to re-evaluate some considerations on the renormalizability of the theory.

ENHANCED DUALITY SYMMETRIES FOR A PAIR OF DIRAC–BORN–INFELD ACTIONS

2012 ◽  
Vol 27 (10) ◽  
pp. 1250056
Author(s):  
HITOSHI NISHINO ◽  
SUBHASH RAJPOOT
Keyword(s):  
Vector Field ◽  
Axial Vector ◽  
Interaction Constant ◽  
Higher Order ◽  
Duality Condition ◽  
Higher Order Terms ◽  
Total Action

We consider a total action composed of two Dirac–Born–Infeld (DBI) actions: one for a vector field Aμ and another for an axial vector field Bμ. We impose a duality condition [Formula: see text], where [Formula: see text] is the Hodge dual of Gμν, and g is a DBI interaction constant. Interestingly, there are two different global duality rotation symmetries in the presence of DBI interactions: (i) [Formula: see text], [Formula: see text], and (ii) δζAμ = - ζBμ, δζBμ = + ζAμ. Both of these symmetry are on-shell symmetries, including nonlinear higher-order terms. The remarkable aspect is that these symmetries are valid even in the presence of DBI interactions. The coupling of this system to N = 1 supergravity is also discussed.

scholarly journals COLOR BOSONIZATION, CHIRAL PARAMETRIZATION OF GLUONIC FIELD AND QCD EFFECTIVE ACTION

2006 ◽  
Vol 21 (35) ◽  
pp. 2649-2661 ◽  
Author(s):  
VICTOR NOVOZHILOV ◽  
YURI NOVOZHILOV
Keyword(s):  
Vector Field ◽  
Gauge Field ◽  
Degrees Of Freedom ◽  
Axial Vector ◽  
Color Space ◽  
Chiral Anomaly ◽  
Chiral Field ◽  
Gauge Invariant ◽  
Low Energies ◽  
Color Vector

We develop a color bosonization approach to treat QCD gauge field ("gluons") at low energies in order to derive an effective color action of QCD taking into account the quark chiral anomaly in the case of SU(2) color. We have found that there exists such a region in the chiral sector of color space, where a gauge field coincides with chirally rotated vector field, while an induced axial vector field disappears. In this region, the unit color vector of chiral field plays a defining role, and a gauge field is parametrized in terms of chiral parameters, so that no additional degrees of freedom are introduced by the chiral field. A QCD gauge field decomposition in color bosonization is a sum of a chirally rotated gauge field and an induced axial-vector field expressed in terms of gluonic variables. An induced axial-vector field defines the chiral color anomaly and an effective color action of QCD. This action admits existence of a gauge invariant d = 2 condensate of induced axial-vector field and mass.

scholarly journals Conformal invariance and the metrication of the fundamental forces

2016 ◽  
Vol 25 (12) ◽  
pp. 1644003 ◽  
Author(s):  
Philip D. Mannheim
Keyword(s):  
String Theory ◽  
Conformal Invariance ◽  
Vector Fields ◽  
Axial Vector ◽  
Gravitational Theory ◽  
Einstein Gravity ◽  
Conformal Gravity ◽  
Yang Mills ◽  
Standard Picture ◽  
Fundamental Forces

We revisit Weyl’s metrication (geometrization) of electromagnetism. We show that by making Weyl’s proposed geometric connection be pure imaginary, not only are we able to metricate electromagnetism, an underlying local conformal invariance makes the geometry be strictly Riemannian and prevents observational gravity from being complex. Via torsion, we achieve an analogous metrication for axial-vector fields. We generalize our procedure to Yang–Mills theories, and achieve a metrication of all the fundamental forces. Only in the gravity sector does our approach differ from the standard picture of fundamental forces, with our approach requiring that standard Einstein gravity be replaced by conformal gravity. We show that quantum conformal gravity is a consistent and unitary quantum gravitational theory, one that, unlike string theory, only requires four spacetime dimensions.

scholarly journals A new approach to anomalous axial vector field theory – II

2021 ◽  
pp. 2150155
Author(s):  
A. K. Kapoor
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Vector Field ◽  
Axial Vector ◽  
Quantum Field ◽  
Stochastic Quantization ◽  
New Approach ◽  
Four Dimensions

This work is continuation of a stochastic quantization program reported earlier. In this paper, we propose a consistent scheme of doing computations directly in four dimensions using conventional quantum field theory methods.

scholarly journals Renormalization of Einstein gravity through a derivative-dependent field redefinition

2018 ◽  
Vol 33 (02) ◽  
pp. 1850016 ◽  
Author(s):  
Brian Slovick
Keyword(s):  
Local Field ◽  
Infinite Number ◽  
Einstein Gravity ◽  
Current Amplitude ◽  
Alternative Solution ◽  
Higher Derivatives ◽  
Renormalizable Theory ◽  
Dependent Field ◽  
Field Redefinition

This work explores an alternative solution to the problem of renormalizability in Einstein gravity. In the proposed approach, Einstein gravity is transformed into the renormalizable theory of four-derivative gravity by applying a local field redefinition containing an infinite number of higher derivatives. It is also shown that the current–current amplitude is invariant with the field redefinition, and thus the unitarity of Einstein gravity is preserved.

scholarly journals TOROIDAL SOLUTIONS IN HOŘAVA GRAVITY

2011 ◽  
Vol 26 (05) ◽  
pp. 925-934 ◽  
Author(s):  
AHMAD GHODSI
Keyword(s):  
Equations Of Motion ◽  
Einstein Gravity ◽  
Horava Gravity ◽  
Renormalizable Theory ◽  
Theory Of Gravity ◽  
Horizon Geometry

Recently a new four-dimensional nonrelativistic renormalizable theory of gravity was proposed by Hořava. This gravity reduces to Einstein gravity at large distances. In this paper we present different toroidal solutions to the equations of motion using the new action for gravity. Our solutions describe the near horizon geometry with slow rotating parameter.

On m-quasi-Einstein spacetimes

2021 ◽  
pp. 2150066
Author(s):  
Absos Ali Shaikh ◽  
Shyamal Kumar Hui ◽  
Akshoy Patra
Keyword(s):  
Vector Field ◽  
Energy Density ◽  
Viscous Fluid ◽  
Cosmological Constant ◽  
Ricci Tensor ◽  
Killing Vector ◽  
Killing Vector Field ◽  
Conformally Flat ◽  
Matter Distribution ◽  
Einstein's Equation

In this paper, we have studied [Formula: see text]-quasi-Einstein spacetimes. Some basic results of such spacetimes are derived. Perfect and viscous fluid [Formula: see text]-quasi-Einstein spacetimes are also studied and the expressions of pressure, cosmological constant and energy density are obtained. We have proved that if the generator [Formula: see text] of an [Formula: see text]-quasi-Einstein spacetime is a Killing vector field, then the spacetime is either conformally flat or of Petrov-type [Formula: see text]. It is also shown that if the function [Formula: see text] of an [Formula: see text]-quasi-Einstein spacetime satisfying Einstein’s equation is harmonic and the matter distribution is perfect fluid, then Segre’ characteristics of the Ricci tensor is [(1,1), 1]. Finally, an example is constructed for the proper existence of such a spacetime.

scholarly journals ON THE TENSOR FORMULATION OF EFFECTIVE VECTOR LAGRANGIANS AND DUALITY TRANSFORMATIONS

1996 ◽  
Vol 11 (13) ◽  
pp. 1069-1080 ◽  
Author(s):  
JOHAN BIJNENS ◽  
ELISABETTA PALLANTE
Keyword(s):  
Vector Field ◽  
Tensor Field ◽  
Axial Vector ◽  
Antisymmetric Tensor ◽  
Vector Mesons ◽  
Massive Vector ◽  
Duality Transformations ◽  
Effective Lagrangian ◽  
Antisymmetric Tensor Field ◽  
Tensor Formulation

Using two different methods inspired by duality transformations we present the equivalence between effective Lagrangians for massive vector mesons using a vector field and an antisymmetric tensor field. This completes the list of explicit field transformations between the various effective Lagrangian methods to describe massive vector and axial vector mesons. Our method automatically generates the point-like terms needed for off-shell equivalence.

scholarly journals Quantum kinetic equation for fluids of spin-1/2 fermions

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Ömer F. Dayi ◽  
Eda Kilinçarslan
Keyword(s):  
Vector Field ◽  
Kinetic Equation ◽  
Coriolis Force ◽  
Transport Theory ◽  
Axial Vector ◽  
Kinetic Equations ◽  
Three Dimensional ◽  
Chiral Anomaly ◽  
Quantum Kinetic Equation ◽  
Complex Scalar

Abstract Fluid of spin-1/2 fermions is represented by a complex scalar field and a four-vector field coupled both to the scalar and the Dirac fields. We present the underlying action and show that the resulting equations of motion are identical to the (hydrodynamic) Euler equations in the presence of Coriolis force. As a consequence of the gauge invariances of this action we established the quantum kinetic equation which takes account of noninertial properties of the fluid in the presence of electromagnetic fields. The equations of the field components of Wigner function in Clifford algebra basis are employed to construct new semiclassical covariant kinetic equations of the vector and axial-vector field components for massless as well as massive fermions. Nonrelativistic limit of the chiral kinetic equation is studied and shown that it generates a novel three-dimensional transport theory which does not depend on spatial variables explicitly and possesses a Coriolis force term. We demonstrated that the three-dimensional chiral transport equations are consistent with the chiral anomaly. For massive fermions the three-dimensional kinetic transport theory generated by the new covariant kinetic equations is established in small mass limit. It possesses the Coriolis force and the massless limit can be obtained directly.

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