Search arXiv⌕ Search

arXiv · hep-th/9902020

A Model of Nonlocal Quantum Electrodynamics : Time's Arrow and EPR-like Quantum Correlation

Abstract

A recent experiment with squeezed light has shown that two-photon absorption by an atom can occur with a linear intensity dependence. We point out that this result verifies a prediction made by us more than a decade ago from an analysis of a nonlocal model of QED. This model had earlier been proposed by us in an ad hoc manner to interpret certain features of multiphoton double ionization and above-threshold ionization in an atom placed in a strong laser field ; in this paper we show that the model can be obtained field- theoretically by demanding covariance of the field Lagrangian under a nonlocal U(1) gauge transformation. The model also makes direct contact with squeezed light, and thus allows us to describe these two completely different scenarios from a unified point of view. We obtain a fundamentally new result from our nonlocal QED, namely that only the past, but not the future, can influence the present - thus establishing a non-thermodynamic arrow of time at the quantum level. We also show that correlations within a quantum system should necessarily be of the EPR-type, a result that agrees with Bell's theorem. These results follow from the simple requirement of energy conservation in matter-radiation interaction. Furthermore, we also predict new and experimentally verifiable results on the basis of our model QED.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T. K. Rai Dastidar, Krishna Rai Dastidar. 1999-02-02. A Model of Nonlocal Quantum Electrodynamics : Time's Arrow and EPR-like Quantum Correlation. https://arxiv.org/abs/hep-th/9902020

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Symmetry-resolved Krylov Complexity and the Uncoloured Tensor Model

The symmetry-resolved Krylov complexity is a useful tool for studying the chaotic properties of systems endowed with symmetries. We investigate the conditions under which an invariant Hermitian operator would have the symmetry-resolved Krylov complexity in a charge subspace identical to the Krylov complexity of the full operator, and find a necessary and sufficient condition that ensures this matching at all temperatures. Further, we study the Krylov complexity of the Uncoloured Tensor Model, a disorder-free kin of the SYK Model, which has a plethora of symmetries. We identify charge subspaces of the same operator in which equipartition holds, as well as those where it doesn't, along with observations on the underlying mechanism behind these. We also find that, within the computational limits, the Krylov complexity, averaged over the symmetry subspace, is bounded above by that of the operator in the full space.

hep-th↗

Non-invertible Selection Rules from Generalized Discrete Gauging of Finite Non-Abelian Symmetries

We investigate non-invertible selection rules originating from the discrete $H$-gauging of theories with an underlying discrete global symmetry group $G$. To systematically describe these theories, we formulate a general framework for $H$-gauged models that incorporates generalized field transformations. Our approach naturally accommodates non-Abelian groups, for which multidimensional irreducible representations play an essential role. In such models with non-Abelian groups, the transformations induced by $H$ non-trivially mix the internal components of $G$-multiplets, potentially projecting out specific degrees of freedom. Consequently, conventional selection rules based on standard tensor product decompositions or conjugacy classes become insufficient. By analyzing the full semidirect product $G \rtimes H$, we introduce projected characters to derive necessary and sufficient conditions for non-vanishing $n$-point bare couplings. Furthermore, we demonstrate that the remaining field components obey an associative fusion-like algebra governed by their Clebsch-Gordan coefficients. Phenomenologically, these selection rules restrict allowed interactions and impose specific relations among coupling constants. We illustrate our results through concrete examples, including $Δ(54) \cong Δ(27)\rtimes \mathbb{Z}_2$ and $S_4 \cong A_4 \rtimes \mathbb{Z}_2$.

hep-th↗

Conformal defects of general dimensions at finite temperature

We consider defect conformal field theories (DCFTs) at finite temperature, where a $p$-dimensional conformal defect wraps the thermal circle. Extending the previous study of line defects to defects of general dimensions, we determine the general forms of the thermal one-point functions of bulk scalars, conserved currents and the stress tensor by imposing the residual symmetry and the conservation laws. The low temperature expansion of the thermal one-point functions is shown to be reproduced by the bulk-defect operator expansion, allowing us to read off the thermal one-point coefficients of defect operators. We examine the general results in four classes of examples with free bulk theories: the trivial defect, free scalar and fermion theories with a boundary, the free scalar theory with a localized $ϕ$ deformation in $d=2\,p+2$ dimensions and the free $\mathrm{O}(N)$ model with a localized $ϕ^2$ deformation in $d=p+2-ε$ dimensions. In the last example with $ε= 1$, where the defect becomes an interface, we find that the thermal one-point functions coincide with those of the free scalar theory with the Dirichlet boundary condition, in accordance with the conjectured factorization of an interface CFT into two decoupled boundary CFTs.

hep-th↗