Induced Gravity in Deconstructed Space at Finite Temperature
We study self-consistent cosmological solutions for an Einstein universe in a graph-based induced gravity model. Especially, we demonstrate specific results for cycle graphs.
gr-qc↗
arXiv subjects
Nahomi Kan
Publications and source records attributed to Nahomi Kan.
Divergences in QED on a Graph
We consider a model of quantum electrodynamics (QED) on a graph. The one-loop divergences in the model are investigated by use of the background field method.
hep-th↗
Induced Gravity from Theory Space
The mass spectrum of a model constructed in a theory space is expressed by eigenvalues of the Laplacian on the graph structure of the theory space. The nature of the one-loop UV divergence in the vacuum energy is then controlled only by the degree matrix of the graph. Using these facts, we can construct models of induced gravity which do not suffer from divergences at the one-loop level.
gr-qc↗
One-loop finite potential for N-2 scalars from N quantum fields
We study the one-loop effective potential induced from quantum fluctuation of a finite number of fields. A series expansion in terms of the modified Bessel functions is useful to evaluate the one-loop effective potential. We find that at most $N-2$ scalars parameterize the one-loop finite potential and the explicit parameterization is shown. The structure of the potential for N=4 is investigated as the simplest case. The implication of the model is discussed.
hep-ph↗
Compactification in deconstructed gauge theory with topologically non-trivial link fields
We investigate the mass spectrum of a scalar field in a world with latticized and circular continuum space where background fields takes a topological configuration. We find that the mass spectrum is related to the characteristic values of Mathieu functions. The gauge symmetry breaking in a similar spacetime is also discussed.
hep-th↗
Multi-graviton theory, a latticized dimension, and the cosmological constant
Beginning with the Pauli-Fierz theory, we construct a model for multi-graviton theory. Couplings between gravitons belonging to nearest-neighbor ``theory spaces'' lead to a discrete mass spectrum. Our model coincides with the Kaluza-Klein theory whose fifth dimension is latticized. We evaluate one-loop vacuum energy in models with a circular latticized extra dimension as well as with compact continuous dimensions. We find that the vacuum energy can take a positive value, if the dimension of the continuous space time is $6, 10,...$. Moreover, since the amount of the vacuum energy can be an arbitrary small value according to the choice of parameters in the model, our models is useful to explain the small positive dark energy in the present universe.
gr-qc↗
Shape of Deconstruction
We construct a six-dimensional Maxwell theory using a latticized extra space, the continuum limit of which is a shifted torus recently discussed by Dienes. This toy model exhibits the correspondence between continuum theory and discrete theory, and give a geometrical insight to theory-space model building.
hep-ph↗
Deconstructing Scalar QED at Zero and Finite Temperature
We calculate the effective potential for the WLPNGB in a world with a circular latticized extra dimension. The mass of the WLPNGB is calculated from the one-loop quantum effect of scalar fields at zero and finite temperature. We show that a series expansion by the modified Bessel functions is useful to calculate the one-loop effective potentials.
hep-th↗
Bulk Fermion Stars with New Dimensions
Many efforts have been devoted to the studies of the phenomenology in particle physics with extra dimensions. We propose degenerate fermion stars with extra dimensions and study what features characterized by the size of extra dimensions should appear in its structure. We find that Kaluza-Klein excited modes arise for the larger scale of extra dimensions and examine the conditions on which different layers should be caused in the inside of the stars. We expound how the extra dimensions affect on physical quantities.
gr-qc↗
Noncommutative gravity in three dimensions coupled to spinning sources
Noncommutative gravity in three dimensions with vanishing cosmological constant is examined. We find a solution which describes a spacetime in the presence of a torsional source. We estimate the phase shift for each partial wave of a scalar field in the spacetime by the Born approximation.
hep-th↗
Equation of state for a classical gas of BPS black holes
A point particle treatment to the statistical mechanics of BPS black holes in Einstein-Maxwell-dilaton theory is developed. Because of the absence of the static potential, the canonical partition function for $N$ BPS black holes can be expressed by the volume of the moduli space for them. We estimate the equation of state for a classical gas of BPS black holes by Padé approximation and find that the result agrees with the one obtained by the mean-field approximation.
gr-qc↗
Fermion Stars with an Extra Dimension
Many efforts have been devoted to the studies of the phenomenology in particle physics with extra dimensions. We propose the degenerate fermion star in the five dimensions, and study what effects caused by the geometry of extra dimensions should appear in its structure. We note that Kaluza-Klein excited modes have effects for the larger scale of extra dimensions and examine the conditions on which different layers should be caused in the inside of the stars. We expound how the effects of the extra dimensions appears on physical quantities.
gr-qc↗