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We show that the principal part of the Dirac Hamiltonian in 3+1 dimensions emerges in a semi-classical approximation from a construction which encodes the kinematics of quantum gravity. The construction is a spectral triple over a…

High Energy Physics - Theory · Physics 2011-03-18 Johannes Aastrup , Jesper M. Grimstrup , Mario Paschke

A pure Dirac's framework for 3D Palatini's theory with cosmological constant is performed. By considering the complete phase space, we find out the full structure of the constraints, and their corresponding algebra is computed explicitly.…

Mathematical Physics · Physics 2015-06-17 Alberto Escalante , Omar Rodríguez Tzompantzi

The physical condition that the expectation values of physical observables are real quantities is used to give a precise formulation of PT-symmetric quantum mechanics. A mathematically rigorous proof is given to establish the physical…

Quantum Physics · Physics 2009-11-10 Ali Mostafazadeh

The hypothesis is suggested that the equation for the Dirac free wave field is, in fact, a group-theoretical relation describing propagation of specific microscopic deviations of space geometry from the euclidean one (closed topological…

Quantum Physics · Physics 2007-06-26 O. A. Olkhov

By using two-component approach to the one-dimensional effective mass Dirac equation bound states are investigated under the effect of two new non-PT-symmetric, and non-Hermitian, exponential type potentials. It is observed that the Dirac…

Quantum Physics · Physics 2009-09-05 Altug Arda , Ramazan Sever

We show how to construct Hamiltonian lattice theories with one exact supersymmetry on arbitrary triangulations of curved space in any number of dimensions. Both bosons and fermions satisfy discrete K\"{a}hler-Dirac equations. The…

High Energy Physics - Theory · Physics 2026-01-06 David Berenstein , Simon Catterall

We define and study the probability current and the Hamiltonian operator for a fully general set of Dirac matrices in a flat spacetime with affine coordinates, by using the Bargmann-Pauli hermitizing matrix. We find that with some weak…

Quantum Physics · Physics 2011-08-31 Mayeul Arminjon , Frank Reifler

In Dirac's canonical quantization theory on systems with second-class constraints, the commutators between the position, momentum and Hamiltonian form a set of algebraic relations that are fundamental in construction of both the quantum…

Quantum Physics · Physics 2015-05-30 Q. H. Liu , L. H. Tang , D. M. Xun

This paper investigates finite-dimensional representations of PT-symmetric Hamiltonians. In doing so, it clarifies some of the claims made in earlier papers on PT-symmetric quantum mechanics. In particular, it is shown here that there are…

Quantum Physics · Physics 2015-06-26 Carl M. Bender , Peter N. Meisinger , Qinghai Wang

In recent reports, suggestions have been put forward to the effect that parity and time-reversal (PT) symmetry in quantum mechanics is incompatible with causality. It is shown here, in contrast, that PT-symmetric quantum mechanics is fully…

Quantum Physics · Physics 2016-04-07 Dorje C. Brody

In this work, we readdress the Dirac equation in the position-dependent mass (PDM) scenario. Here, one investigates the quantum dynamics of non-Hermitian fermionic particles with effective mass assuming a $(1+1)$-dimension flat spacetime.…

Quantum Physics · Physics 2023-03-22 F. C. E. Lima , L. N. Monteiro , C. A. S. Almeida

The relativistic Dirac equation in four-dimensional spacetime reveals a coherent relation between the dimensions of spacetime and the degrees of freedom of fermionic spinors. A massless Dirac fermion generates new symmetries corresponding…

High Energy Physics - Theory · Physics 2017-09-01 Yue-Liang Wu

The Hamiltonian formulation of Horava gravity is derived. In a closed universe the Hamiltonian is a sum of generators of gauge symmetries, the foliation-preserving diffeomorphisms, and vanishes on shell. The scalar constraint is second…

High Energy Physics - Theory · Physics 2012-01-17 William Donnelly , Ted Jacobson

A rigorous \textit{ab initio} derivation of the (square of) Dirac's equation for a single particle with spin is presented. The general Hamilton-Jacobi equation for the particle expressed in terms of a background Weyl's conformal geometry is…

Quantum Physics · Physics 2011-07-19 Enrico Santamato

A physical requirement on the Hamiltonian operator in quantum mechanics is that it must generate real energy spectrum and unitary time evolution. While the Hamiltonians are Dirac Hermitian in conventional quantum mechanics, they observe…

Mathematical Physics · Physics 2018-07-31 Minyi Huang , Asutosh Kumar , Junde Wu

We re-examine the non Hermitian position coordinate of Dirac's equation, in the light of his own insights and conclude that this, and the Dirac equation itself is symptomatic of an underlying Noncommutative Geometry.

General Physics · Physics 2007-05-23 B. G. Sidharth

We apply Dirac's Hamiltonian approach to study the canonical structure of the teleparallel form of general relativity without matter fields. It is shown, without any gauge fixing, that the Hamiltonian has the generalized Dirac-ADM form, and…

High Energy Physics - Theory · Physics 2010-01-27 M. Blagojevic , I. A. Nikolic

Generalized PT symmetry provides crucial insight into the sign problem for two classes of models. In the case of quantum statistical models at non-zero chemical potential, the free energy density is directly related to the ground state…

High Energy Physics - Theory · Physics 2010-09-06 Peter N. Meisinger , Michael C. Ogilvie , Timothy D. Wiser

The two-dimensional Dirac Hamiltonian with equal scalar and vector potentials has been proved commuting with the deformed orbital angular momentum $L$. When the potential takes the Coulomb form, the system has an SO(3) symmetry, and…

Quantum Physics · Physics 2008-10-13 Fu-Lin Zhang , Ci Song , Jing-Ling Chen

One-dimensional scattering mediated by non-Hermitian Hamiltonians is studied. A schematic set of models is used which simulate two point interactions at a variable strength and distance. The feasibility of the exact construction of the…

Quantum Physics · Physics 2008-06-26 Miloslav Znojil