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arXiv · 1007.2499

Noncommutative Double Scalar Fields in FRW Cosmology as Cosmical Oscillators

Behrooz Malekolkalami·Mehrdad Farhoudi
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Abstract

We investigate effects of noncommutativity of phase space generated by two scalar fields conformally coupled to curvature in FRW cosmology. We restrict deformation of minisuperspace to noncommutativity between scalar fields and between their canonical conjugate momenta. The investigation is carried out by means of comparative analysis of mathematical properties of time evolution of variables in classical model and wave function of universe in quantum level. We find that impose of noncommutativity causes more ability in tuning time solutions of scalar fields and hence, has important implications in evolution of universe. We get that noncommutative parameter in momenta sector is the only responsible parameter for noncommutative effects in flat universes. A distinguishing feature of noncommutative solutions of scalar fields is that they can be simulated with well known harmonic oscillators, depend on values of spatial curvature. Namely free, forced and damped harmonic oscillators corresponding to flat, closed and open universes. In this respect, we call them cosmical oscillators. In closed universes, when noncommutative parameters are small, cosmical oscillators have analogous effect with familiar beating effect in sound phenomenon. The existence of non-zero constant potential does not change solutions of scalar fields, but modifies scale factor. An interesting feature of well behaved solutions of wave functions is that functional form of its radial part is the same as commutative ones provided that given replacement of constants, caused by noncommutative parameters, is performed. Further, Noether theorem has been employed to explore effects of noncommutativity on underlying symmetries in commutative frame. Two of six Noether symmetries of flat universes, in general, are retained in noncommutative case, and one out of three ones in non flat universes.

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Behrooz Malekolkalami, Mehrdad Farhoudi. 2010-11-23. Noncommutative Double Scalar Fields in FRW Cosmology as Cosmical Oscillators. https://doi.org/10.1088/0264-9381%2F27%2F24%2F245009

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