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M. Zarei

Publications and source records attributed to M. Zarei.

6 recordsLinked to original sources
arXiv2012

Slow-roll trajectories in Chromo-Natural and Gauge-flation Models, an exhaustive analysis

We present an exhaustive analysis on the classical solutions of the Chromo-natural model. We showed that starting from an arbitrary axion field value $χ_0\in(0,fπ)$, it is possible to have successful slow-roll inflation and working out the analytical solution of the number of e-folding, we determine the allowed region of the parameters corresponding to each $χ_0$ value. Having the allowed parameter region, then we study the behavior of the solutions respect to the initial value of the axion field.

hep-th↗
arXiv2010

Generation of circular polarization of the CMB

According to the standard cosmology, near the last scattering surface, the photons scattered via Compton scattering are just linearly polarized and then the primordial circular polarization of the CMB photons is zero. In this work we show that CMB polarization acquires a small degree of circular polarization when a background magnetic field is considered or the quantum electrodynamic sector of standard model is extended by Lorentz-noninvariant operators as well as noncommutativity. The existence of circular polarization for the CMB radiation may be verified during future observation programs and it represents a possible new channel for investigating new physics effects.

hep-th↗
arXiv2008

Effective Field Theory of a Locally Noncommutative Space-Time and Extra Dimensions

We assume that the noncommutativity starts to be visible continuously from a scale $Λ_{NC}$. According to this assumption, a two-loop effective action is derived for noncommutative $ϕ^{4}$ and $ϕ^{3}$ theories from a Wilsonian point of view. We show that these effective theories are free of UV/IR mixing phenomena. We also investigate the positivity constraint on coefficients of higher dimension operators present in the effective theory. This constraint makes the low energy theory to be UV completion of a full theory. Finally, we discuss noncommutativity and extra dimensions. In our effective theories formulated on noncommutative extra dimensions, if the campactification scale $Λ_{c}$ is less than the scale $Λ_{NC}$, the theory will not suffer from UV/IR mixing.

hep-th↗
arXiv2006

Aharonov-Casher effect for spin one particles in a noncommutative space

In this work the Aharonov-Casher (AC) phase is calculated for spin one particles in a noncommutative space. The AC phase has previously been calculated from the Dirac equation in a noncommutative space using a gauge-like technique [17]. In the spin-one, we use kemmer equation to calculate the phase in a similar manner. It is shown that the holonomy receives non-trivial kinematical corrections. By comparing the new result with the already known spin 1/2 case, one may conjecture a generalized formula for the corrections to holonomy for higher spins.

hep-th↗
arXiv2006

Cancellation of soft and collinear divergences in noncommutative QED

In this paper, we investigate the behavior of non-commutative IR divergences and will also discuss their cancellation in the physical cross sections. The commutative IR (soft) divergences existing in the non-planar diagrams will be examined in order to prove an all order cancellation of these divergences using the Weinberg's method. In non-commutative QED, collinear divergences due to triple photon splitting vertex, were encountered, which are shown to be canceled out by the non-commutative version of KLN theorem. This guarantees that there is no mixing between the Collinear, soft and non-commutative IR divergences.

hep-th↗