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M. N. Mnatsakanova

Publications and source records attributed to M. N. Mnatsakanova.

17 recordsLinked to original sources

CPT Violation, Mirror World and Implications for Baryon Asymmetry

We propose a novel model in which the Universe is created as a pair of coordinate-reversed counterparts, forming a globally CPT-symmetric system that permits local CPT violations within each sector. This framework naturally introduces a mirror universe with opposite chiralities and reversed microscopic time coordinates, providing a geometric interpretation of time reversal without relying on initial-final state interchange. We investigate the consequences of local CPT violation in each universe, which induces a mass difference between the real inflaton and anti-inflaton fields. Such an asymmetry can modify reheating temperatures and naturally generate the observed matter-antimatter asymmetry in both universes.

hep-ph↗

Induced CP-violation in the Euler-Heisenberg Lagrangian

In this paper, we examine the behaviour of the Euler-Heisenberg effective action in the presence of a novel axial coupling among the gauge field and the fermionic matter. This axial coupling is responsible to induce a CP-violating term in the extended form of the Euler-Heisenberg effective action, which is generated naturally through the analysis of the box diagram. However, this anomalous model is not a viable extension of QED, and we explicitly show that the induced CP-violating term in the Euler-Heisenberg effective Lagrangian is obtained only by adding an axial coupling to the ordinary QED Lagrangian. In order to perform our analysis, we use a parametrization of the vector and axial coupling constants, $g_{v}$ and $g_{a}$, in terms of a new coupling $β$. Interestingly, this parametrization allows us to explore a hidden symmetry under the change of $g_{v}\leftrightarrow g_{a}$ in some diagrams. This symmetry is explicitly observed in the analysis of the box diagram, where we determine the $λ_i$ coefficients of $\cal{L}_{\rm ext.}^{\rm \small EH}=λ_{1}\cal{F}^{2}+λ_{2}\cal{G}^{2}+λ_{3}\cal{F}\cal{G}$, specially the coefficient $λ_3$ related with the CP-violating term due to the axial coupling. As a phenomenological application of the results, we compute the relevant cross section for the light by light scattering through the extended Euler-Heisenberg effective action.

hep-th↗

Seiberg-Witten Map with Lorentz-Invariance and Gauge-Covariant Star Product

We develop the Seiberg-Witten map using the gauge-covariant star product with the noncommutativity tensor $θ^{μν}(x)$. The latter guarantees the Lorentz invariance of the theory. The usual form of this map and its other recent generalizations do not consider such a covariant star product. We construct the Seiberg-Witten map for the gauge parameter, the gauge field and the strength tensor to the first order in the noncommutativity parameter $θ^{μν}(x)$. Prescription for the generalization of the map to higher orders is also given. Interestingly, the associativity of the covariant star product both in the first and second orders requires the same constraints, namely, on the $θ^{μν}(x)$ and on the space-time connection. This fact suggests that the same constraints could be enough to ensure the associativity in all orders. The resulting Seiberg-Witten map applies both to the internal and space-time gauge theories. Comparisons with the Seiberg-Witten map based on other (non-covariant) star products are given and some characteristic properties are also presented. As an application, we consider the $GL(2, C)$ noncommutative gauge theory of gravitation, in which it is shown that the connection determines a space-time with symplectic structure (as proposed by Zumino et al [AIP Conf. Proc. 1200 (2010), 204, arXiv:0910.0459]). This example shows that the constraints required for the associativity of the gauge-covariant star product can be satisfied. The presented $GL(2, C)$ noncommutative gauge theory of gravitation is also compared to the one (given by Chamseddine [Phys. Rev. D 69 (2004), 024015, hep-th/0309166]) with non-covariant star product.

hep-th↗

Towards an Axiomatic Formulation of Noncommutative Quantum Field Theory. II

Classical results of the axiomatic quantum field theory, namely the irreducibility of the set of field operators, Reeh and Schlieder's theorems and generalized Haag's theorem, are proven in $SO(1,1)$ invariant quantum field theory, of which an important example is noncommutative quantum field theory. New consequences of generalized Haag's theorem are obtained in $SO(1,3)$ invariant theories. It has been proven that the equality of four-point Wightman functions in two theories leads to the equality of elastic scattering amplitudes and thus the total cross-sections in these theories.

hep-th↗

Haag's Theorem in Noncommutative Quantum Field Theory

Haag's theorem was extended to noncommutative quantum field theory in a general case when time does not commute with spatial variables. It was proven that if S-matrix is equal to unity in one of two theories related by unitary transformation, then the corresponding one in another theory is equal to unity as well. In fact this result is valid in any SO(1,1) invariant quantum field theory, of which an important example is noncommutative quantum field theory.

math-ph↗

Towards an Axiomatic Formulation of Noncommutative Quantum Field Theory

We propose new Wightman functions as vacuum expectation values of products of field operators in the noncommutative space-time. These Wightman functions involve the $\star$-product among the fields, compatible with the twisted Poincaré symmetry of the noncommutative quantum field theory (NC QFT). In the case of only space-space noncommutativity ($θ_{0i}=0$), we prove the CPT theorem using the noncommutative form of the Wightman functions. We also show that the spin-statistics theorem, demonstrated for the simplest case of a scalar field, holds in NC QFT within this formalism.

hep-th↗

Haag's theorem in S O (1, k) invariant quantum field theory

Generalized Haag's theorem has been proved in S O (1, k) invariant quantum field theory. Apart from the above mentioned k+1 variables there can be arbitrary number of additional coordinates including noncommutative ones in the theory. New consequences of generalized Haag's theorem are obtained. It has been proved that the equality of four-point Wightman functions in two theories leads to the equality of elastic scattering amplitudes and thus the total cross-sections in these theories. In space-space noncommutative quantum field theory in four-dimensional case it has been proved that if in one of the theories under consideration S-matrix is equal to unity, then in another theory S-matrix is unity as well.

math-ph↗

Rigorous Definition of Quantum Field Operators in Noncommutative Quantum Field Theory

The space, on which quantum field operators are given, is constructed in any theory, in which the usual product between test functions is substituted by the $\star$-product (the Moyal-type product). The important example of such a theory is noncommutative quantum field theory (NC QFT). This construction is the key point in the derivation of the Wightman reconstruction theorem.

math-ph↗

Jost-Lehmann-Dyson Representation, Analyticity in Angle Variable and Upper Bounds in Noncommutative Quantum Field Theory

The existence of Jost-Lehmann-Dyson representation analogue has been proved in framework of space-space noncommutative quantum field theory. On the basis of this representation it has been found that some class of elastic amplitudes admits an analytical continuation into complex \cos\vartheta plane and corresponding domain of analyticity is Martin ellipse. This analyticity combined with unitarity leads to Froissart-Martin upper bound on total cross section.

hep-th↗

Analyticity and Forward Dispersion Relations in Noncommutative Quantum Field Theory

We derive the analytical properties of the elastic forward scattering amplitude of two scalar particles from the axioms of the noncommutative quantum field theory. For the case of only space-space noncommutativity, i.e. $θ_{0i}=0$, we prove the dispersion relation which is similar to the one in commutative quantum field theory. The proof in this case is based on the existence of the analog of the usual microcausality condition and uses the Lehmann-Symanzik-Zimmermann (LSZ) or equivalently the Bogoliubov-Medvedev-Polivanov (BMP) reduction formalisms. The existence of the latter formalisms is also shown. We remark on the general noncommutative case, $θ_{0i}\neq0$, as well as on the nonforward scattering amplitude and mention their peculiarities.

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