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We have recently proposed a pre-quantum, pre-space-time theory as a matrix-valued Lagrangian dynamics on an octonionic space-time. This theory offers the prospect of unifying internal symmetries of the standard model with pre-gravitation.…

General Physics · Physics 2022-06-09 Tejinder P. Singh

The possibility of parity violation in a gravitational theory with torsion is extensively explored in four and higher dimensions. In the former case,we have listed our conclusions on when and whether parity ceases to be conserved, with both…

High Energy Physics - Theory · Physics 2009-11-07 Biswarup Mukhopadhyaya , Somasri Sen , Soumitra SenGupta , Saurabh Sur

Quantum field theory has been established on symmetries, but their fundamentality could be limited as practical calculations of physical observations are not based on interacting Lagrangian. The requirement of Lorentz invariance on vacuum…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. C. Yoon

In this study we prove that the Pauli interaction -- which is associated with a length parameter -- emerges when the minimal coupling recipe is applied to the non-degenerate version of the Dirac Lagrangian. The conventional Dirac Lagrangian…

General Relativity and Quantum Cosmology · Physics 2024-08-12 J. Struckmeier , D. Vasak , A. Redelbach , H. Stöcker

We analyze parity-violating nucleon-nucleon scattering at energies E<m_\pi^2/M using the effective field theory appropriate for this regime. The minimal Lagrangian for short-range parity-violating NN interactions is written in an operator…

Nuclear Theory · Physics 2009-05-13 Daniel R. Phillips , Matthias R. Schindler , Roxanne P. Springer

We investigate the quantum effects of the non-minimal matter-gravity couplings derived by Cangemi and Jackiw in the realm of a specific fermionic theory, namely the abelian Thirring model on a Riemann surface of genus zero and one. The…

High Energy Physics - Theory · Physics 2016-09-06 L. Griguolo , D. Seminara

We study the parity breaking effective action in 2+1 dimensions, generated, at finite temperature, by massive fermions interacting with a non-Abelian gauge background. We explicitly calculate, in the static limit, parity violating…

High Energy Physics - Theory · Physics 2009-11-07 F. T. Brandt , Ashok Das , J. Frenkel

The Ashtekar-Barbero-Immirzi formulation of General Relativity is extended to include spinor matter fields. Our formulation applies to generic values of the Immirzi parameter and reduces to the Ashtekar-Romano-Tate approach when the Immirzi…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Simone Mercuri

The most important problem of fundamental Physics is the quantization of the gravitational field. A main difficulty is the lack of available experimental tests that discriminate among the theories proposed to quantize gravity. Recently,…

High Energy Physics - Theory · Physics 2009-11-10 Jorge Alfaro

We perform the Lorentz-covariant Hamiltonian analysis of two Lagrangian action principles that describe general relativity as a constrained BF theory and that include the Immirzi parameter. The relation between these two Lagrangian actions…

General Relativity and Quantum Cosmology · Physics 2012-09-04 Mariano Celada , Merced Montesinos

Recently, gravitational gauge theories with torsion have been discussed by an increasing number of authors from a classical as well as from a quantum field theoretical point of view. The Einstein-Cartan(-Sciama-Kibble) Lagrangian has been…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Peter Baekler , Friedrich W. Hehl

In a space-time with torsion, the action for the gravitational field can be extended with a parity-violating piece. We show how to obtain such a piece from geometry itself, by suitably modifying the affine connection so as to include a…

High Energy Physics - Theory · Physics 2011-08-17 Biswarup Mukhopadhyaya , Soumitra Sengupta

Holst term represents an interesting addition to the Einstein-Cartan theory of gravity with torsion. When this term is present the contact interactions between vector and axial vector fermion currents gain an extra parity-violating…

High Energy Physics - Theory · Physics 2014-09-01 Ilya L. Shapiro , Poliane M. Teixeira

Bombagcino investigated the role of Immirzi parameter when promoted to a field in Einstein-Cartan-Holst black hole and they found that the Immirzi field acts similar to the axion field, as both axial pseudo-vector and vectorial torsion…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-10 Zhi Fu Gao , Biao Peng Li , L. C. Garcia de Andrade

The emergence of loop quantum gravity over the past two decades has stimulated a great resurgence of interest in unifying general relativity and quantum mechanics. Amongst a number of appealing features of this approach are the intuitive…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles H. -T. Wang

Canonical gravity in real Ashtekar-Barbero variables is generalized to allow for fermionic matter. The resulting torsion changes several expressions in Holst's original vacuum analysis, which are summarized here. This in turn requires…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Martin Bojowald , Rupam Das

Fermions play a special role in homogeneous models of quantum cosmology because the exclusion principle prevents them from forming sizable matter contributions. They can thus describe the matter ingredients only truly microscopically and it…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Rupam Das

By adopting a methodology proposed by R.J. Adler \etl, we study the interesting analogy between the fermion-gravity and the fermion-electromagnetic interactions in the presence of the minimal Lorentz-violating (LV) fermion coefficients. The…

High Energy Physics - Phenomenology · Physics 2023-01-11 Cheng Ye , Zhi Xiao

We develop an effective field theory to describe the coupling of non-thermal quantum black holes to particles such as those of the Standard Model. The effective Lagrangian is determined by imposing that the production cross section of a…

High Energy Physics - Phenomenology · Physics 2015-05-28 Xavier Calmet , Dionysios Fragkakis , Nina Gausmann

It is known that the Schwinger mechanism of vector-like QED theory is afflicted by a logarithmic singularity under background electromagnetic field due to a hypothetical massless charged fermion. We extend singularity analysis to a more…

High Energy Physics - Phenomenology · Physics 2022-09-07 M. Yoshimura