arXiv subjects

Takayuki Nakajima

Publications and source records attributed to Takayuki Nakajima.

4 recordsLinked to original sources

arXiv2017

Visible transitions in Ag-like and Cd-like lanthanide ions

We present visible spectra of Ag-like ($4d^{10}4f$) and Cd-like ($4d^{10}4f^2$) ions of Ho (atomic number $Z=67$), Er (68), and Tm (69) observed with a compact electron beam ion trap. For Ag-like ions, prominent emission corresponding to the M1 transitions between the ground state fine structure splitting $4f_{5/2}$--$4f_{7/2}$ is identified. For Cd-like ions, several M1 transitions in the ground state configuration are identified. The transition wavelength and the transition probability are calculated with the relativistic many-body perturbation theory and the relativistic CI + all-order approach. Comparisons between the experiments and the calculations show good agreement.

physics.atom-ph↗

arXiv1998

Numerical Studies of the Double Scaling Limit in Large N Reduced Model

We study the two-dimensional Eguchi-Kawai model as a toy model of the IIB matrix model, which has been recently proposed as a nonperturbative definition of the type IIB superstring theory. While the planar limit of the model is known to reproduce the two-dimensional Yang-Mills theory, we find through Monte Carlo simulation that the model allows a different large $N$ limit, which can be considered as the double scaling limit in matrix models.

hep-lat↗

arXiv1998

Numerical Study of the Double Scaling Limit in Two-Dimensional Large N Reduced Model

We study the two-dimensional Eguchi-Kawai model as a toy model of the IIB matrix model, which has been recently proposed as a nonperturbative definition of the type IIB superstring theory. While the planar limit of the model is known to reproduce the two-dimensional Yang-Mills theory, we find through Monte Carlo simulation that the model allows a different large N limit, which can be considered as the double scaling limit in matrix models.

hep-th↗

arXiv1996

The Continuum Limit of One-Dimensional Quantum Regge Calculus with Massive Bosons

The most essential problems in Regge calculus discretization are the definitions of the partition function and the integral measure for link--length. In recent work, by considering the one--dimensional case, it was suggested that we should define the partition function in a certain form. But in that work, the model which authors used was over simplified hence the conclusions may be unreliable. To confirm their claim, we consider a case that is more realistic.

hep-lat↗