arXiv subjects

E. B. Manoukian

Publications and source records attributed to E. B. Manoukian.

10 recordsLinked to original sources

arXiv2013

The Graviton Propagator with a Non-Conserved External Generating Source

A novel general expression is obtained for the graviton propagator from Lagrangian field theory by taking into account the necessary fact that in the functional differential approach of quantum field theory, in order to generate non-linearities in gravitation and interactions with matter, the external source $T_{μν}$, coupled to the gravitational field, should \textit{a priori} not be conserved $\partial^μT_{μν}\neq 0$, so variations with respect to its ten components may be varied \textit{independently}. The resulting propagator is the one which arises in the functional approach and does \textit{not} coincide with the corresponding time-ordered product of two fields and it includes so-called Schwinger terms. The quantization is carried out in a gauge corresponding to physical states with two polarization states to ensure positivity in quantum applications.

hep-th↗

arXiv2013

Gravitons, induced geometry and expectation value formalism at finite temperature

After establishing the positivity constraint and spin content of the theory for gravitons interacting with a necessarily, and \textit{a priori}, \textit{non}-conserved external energy-momentum tensor, the expectation value formalism of the theory is developed at \textit{finite} temperature in the functional \textit{differential} treatment of quantum field theory. The necessity of having, \textit{a priori}, a non-conserved external energy-momentum tensor is an obvious technical requirement so that its respective ten components may be varied \textit{independently} in order to generate expectation values and non-linearities in the theory. The covariance of the \textit{induced} Riemann curvature tensor, in the initial vacuum, is established even for the quantization in a gauge corresponding only to two physical states of the gravitons as established above. As an application, the \textit{induced} correction to the metric and the underlying geometry is investigated due to a closed string arising from the Nambu action as a solution of a circularly oscillating string as, perhaps, the simplest generalization of a limiting point-like object. Finally it is discussed on why the geometry of spacetime may, in general, depend on temperature due to radiative corrections and its physical significance is emphasized.

hep-th↗

arXiv2013

Quantum Field Theory Analysis of Polarizations Correlations, Entanglement and Bell's Inequality: Explicit Processes

This paper provides explicit and detailed quantum field theory (QFT) computations of polarizations correlations of emerging particles in several processes in QED, Electroweak Theory, and even in particle productions from strings, and hence are based on dynamical theries. The novel properties observed in the computations of such polarizations correlations, as predicted by QFT, is that they depend on the speed of the colliding particles, and, in some cases, even on coupling parameters ratios as well as on mass ratios of the underlying theory. These investigations clearly show that arguments based simply on combining spins to generate probabilities of such polarization correlations are not reliable. The novel properties obtained, with details of derivations provided here, hopefully would call for experiments on polarizations correlations which would monitor speeds of colliding particles, and, would, in turn, lead to new tests of the fundamental interactions of QFT such as of QED and of the Electroweak Theory.

hep-th↗

arXiv2005

Polarization Correlations in Pair Production from Charged and Neutral Strings

Polarization correlations of $e^{+}e^{-}$ pair productions from charged and neutral Nambu strings are investigated, via photon and graviton emissions, respectively and explicit expressions for their corresponding probabilities are derived and found to be \textit{speed} dependent. The strings are taken to be circularly oscillating closed strings, as perhaps the simplest solution of the Nambu action. In the extreme relativistic case, these probabilities coincide, but, in general, are different, and such inquiries, in principle, indicate whether the string is charged or uncharged. It is remarkable that these dynamical relativistic quantum field theory calculations lead to a clear violation of Local Hidden Variables theories.

hep-th↗

arXiv2004

Field Theory Methods in Classical Dynamics

A Dirac picture perturbation theory is developed for the time evolution operator in classical dynamics in the spirit of the Schwinger-Feynman-Dyson perturbation expansion and detailed rules are derived for computations. Complexification formalisms are given for the time evolution operator suitable for phase space analyses, and then extended to a two-dimensional setting for a study of the geometrical Berry phase as an example. Finally a direct integration of Hamilton's equations is shown to lead naturally to a path integral expression, as a resolution of the identity, as applied to arbitrary functions of generalized coordinates and momenta.

hep-th↗

arXiv2004

Projection of relativistically moving objects on a two-dimensional plane, the `train' paradox and the visibility of the Lorentz contraction

Although many papers have appeared on the theory of photographing relativistically moving objects, pioneered by the classic work of Penrose and Terrell, three problems remain outstanding. (1) There does not seem to exist a general formula which gives the projection of a relativistically moving object, applicable to any object no matter how complicated, on a two-dimensional plane in conformity with Terrell's observation. (2) No resolution seems to have been provided for the associated so-called `train' paradox. (3) No analytical demonstration seems to have been offered on how the Lorentz contraction may be actually detected on a photograph. This paper addresses all of these three problems. The analysis does not require any more than trigonometry and elementary differentiation.

physics.class-ph↗

arXiv2004

Joint Probabilities of Photon polarization Correlations in $e^{+}e^{-}$ Annihilation

Joint probability distributions of photon polarization correlations are computed, as well as those corresponding to the cases when only one of the photon's polarization is measured in $e^{+}e^{-}$ annihilation, in flight, in QED. This provides a dynamical, rather than a kinematical, description of photon polarization correlations as stemming from the ever precise and realistic QED theory. Such computations may be relevant to recent and future experiments involved in testing Bell-like inequalities as described.

quant-ph↗

arXiv2004

Speed dependent polarization correlations in QED and entanglement

Exact computations of polarizations correlations probabilities are carried out in QED, to the leading order, for initially polarized as well as unpolarized particles. Quite generally they are found to be speed dependent and are in clear violation of Bells inequality of Local Hidden Variables (LHV) theories. This dynamical analysis shows how speed dependent entangled states are generated. These computations, based on QED are expected to lead to new experiments on polarization correlations monitoring speed in the light of Bells theorem. The paper provides a full QED treatment of the dynamics of entanglement.

quant-ph↗

arXiv2004

Explicit expression for the photon number emission in synchrotron radiation

An explicit and remarkably simple one-dimensional integral expression is derived for the mean number $ $ of photons emitted per revolution in synchrotron radiation. The familiar high-energy expression $5πα/\sqrt{3(1-β^2)}$, printed repeatedly in the literature, is found to be inaccurate and only truly asymptotic with relative errors of 160%, 82% for $β=0.8$, 0.9, respectively. A new improved high-energy expression for $ $ is given.

physics.acc-ph↗

arXiv2004

Photon number emission in synchrotron radiation: Systematics for high-energy particles

A recent derivation of an explicit elementary expression for the mean number $ $ of photons emitted per revolution in synchrotron radiation allows a systematic high-energy analysis leading to the result $ \simeq 5πα/\sqrt{3(1-β^2)}+a_0α+πα\sqrt{1-β^2}/10\sqrt{3}$ where $a_0$ is a constant, with relative errors of 2.2%, 0.64%, 0.017%, in comparison to the well-known formula tabulated in the literature of 160%, 82%, 17% for $β=0.8$, 0.9, 0.99, respectively.

hep-ph↗