arXiv subjects

Kohjiroh Takimoto

Publications and source records attributed to Kohjiroh Takimoto.

3 recordsLinked to original sources

arXiv2020

Accelerating cosmologies in an integrable model with noncommutative minisuperspace variables

We study classical and quantum noncommutative cosmology with a Liouville-type scalar degree of freedom. The noncommutativity is imposed on the minisuperspace variables through a deformation of the Poisson algebra. In this paper, we investigate the effects of noncommutativity of minisuperspace variables on the accelerating behavior of the cosmic scale factor. The probability distribution in noncommutative quantum cosmology is also studied and we propose a novel candidate for interpretation of the probability distribution in terms of noncommutative arguments.

gr-qc↗

arXiv2020

Equivalent Hamiltonian approach to quantum cosmology of integrable models

We propose an approach to quantum cosmology of integrable models. To analyze the models with two dynamical variables, we introduce equivalent Hamiltonians in reduced phase spaces, which are obtained with the aid of the Faddeev--Jackiw method. Quantum dynamics of the models can be studied by using the equivalent Hamiltonians with various techniques.

gr-qc↗

arXiv2018

Integrable higher-dimensional cosmology with separable variables in an Einstein-dilaton-antisymmetric field theory

We consider a $D$-dimensional cosmological model with a dilaton field and two $(D-d-1)$-form field strengths which have nonvanishing fluxes in extra dimensions. Exact solutions for the model with a certain set of couplings are obtained by separation of three variables. Some of the solutions describe accelerating expansion of the $d$-dimensional space. Quantum cosmological aspects of the model are also briefly mentioned.

hep-th↗