arXiv subjects
Publications and source records attributed to Keiichi Akama.
We incorporate confining effects into statistical formulation of quantum chromodynamics (QCD). It implies that quark-gluon clusters existed in the early universe, triggering the information accumulation in nature. The confinement-driven clustering would explain the reason why the quark-gluon plasma in the heavy-ion ollision experiments looks like liquid unlike the QCD expectation.
To account for the origin of information accumulation in nature despite the entropy-increase law, we advocate a universal mechanism due to competition/selection of general composite entities, from simple to complex. To confirm its universality, we show that even simplest composites such as an atom, a molecule etc. are subject to this mechanism and accumulate information.
Starting with the Nambu-Goto action of the braneworld embedded in a curved bulk, we derive the precise expressions for the quantum induced effects due to small fluctuations of the brane. To define the brane fluctuations invariantly, we introduce the Riemannian coordinate system for the subspace normal to the braneworld. It will turn out that we can systematically incorporate the effects of bulk curvature, and that the induced effects depend on the extrinsic curvature and the normal-connection gauge field as well as on bulk curvature components at the brane.
We present a comprehensive formalism to derive precise expressions for the induced gravity of the braneworld, assuming the dynamics of the Dirac-Nambu-Goto type. The quantum fluctuations of the brane at short distances give rise to divergences, which should be cutoff at the scale of the inverse thickness of the brane. It turns out that the induced-metric formula is converted into an Einstein-like equation via the quantum effects. We determine the coefficients of the induced cosmological and gravity terms, as well as those of the terms including the extrinsic curvature and the normal connection gauge field. The latter is the characteristic of the brane induced gravity theory, distinguished from ordinary none-brane induced gravity.
It is argued that the braneworld gravity under the Schwarzschild ansatz should obey three essential equations on the brane, and they are solved exactly. We express the general solution of the fundamental equations of the braneworld in power series of the brane normal coordinate. The power series are derived by solving three independent components of the bulk Einstein equation, and the coefficients are recursively determined in terms of five functions on the brane. The other components of the bulk Einstein equation are automatically satisfied, as far as the five on-brane functions obey three essential equations. They are the radial-extra and the extra-extra components of the bulk Einstein equation on the brane, and the equation of motion of the brane. Therefore the solution includes two arbitrary functions on the brane. We show that the essential equations are exactly solved by choosing an appropriate set of the two arbitrary functions. The arbitrariness may affect the predictive powers on the Newtonian and the post-Newtonian evidences.
The general solution for the static, spherical and asymptotically flat braneworld is derived by solving the bulk Einstein equation and braneworld dynamics. We show that it involves a large arbitrariness, which reduces the predictability of the theory. Ways out of the difficulty are discussed.
General solutions for braneworld dynamics coupled with the bulk Einstein equation are derived under the Schwarzschild ansatz. They relate the brane metric to the exterior configurations, and establish fine tuning conditions for the braneworlds to reproduce successes of the Einstein gravity.
It is argued that the Einstein equation on a braneworld at low curvature cannot be derived from its classical brane dynamics (i. e. dynamics of the brane as a classical object in the higher dimensional spacetime) as far as the action of the system has smooth low-curvature limit. We discuss possible solutions to the problem.
We study the model of a composite-scalar made of a pair of scalar fields in 6-2 epsilon dimensions, using equivalence to the renormalizable three-elementary-scalar model under the "compositeness condition." In this model, the composite-scalar field is induced by the quantum effects through the vacuum polarization of elementary-scalar fields with 2N species. We first investigate scale dependences of the coupling constant and masses, in the renormalizable three-elementary-scalar model, and derive the results for the composite model by imposing the compositeness condition. The model exhibits the formerly found general property that the coupling constant of the composite field is independent of the scale.
We show that the coupling constant of a quantum-induced composite field is scale invariant due to its compositeness condition. It is first demonstrated in next-to-leading order in 1/N in typical models, and then we argue that it holds exactly.
We derive and solve the compositeness condition for the SU(N_c) gauge boson coupling with N_s scalar fields at the next-to-leading order in 1/N_s and the leading order in ln(Λ^2) (Λis the compositeness scale). It turns out that the argument of gauge-boson compositeness (with a large Λ) is successful only when N_s/N_c>22, in which the asymptotic freedom fails, as is in the previously investigated case with fermionic matter.
We show that the renormalization group beta functions in the Nambu-Jona-Lasinio model identically vanish in all order due to the compositeness condition. Accordingly the effective coupling constants are entirely fixed and do not run with the renormalization scale.
The scale invariance of the coupling constant in the induced gauge theory due to its compositeness condition is demonstrated in the renormalization group flow of the finite-cutoff gauge theory at the leading order in 1/N, where N is the number of the matter fermion species.
We investigate the renormalization group flow of the Yukawa model with a fixed momentum cutoff at the leading order in 1/N, where N is the number of the fermion species. We demonstrate the scale invariance of coupling constants of the Nambu-Jona-Lasinio model.
We introduce a probabilistic measure of naturalness (naturalness level) to fix naturalness bounds quantitatively. It is applied to the anomalous magnetic moments and the electric dipole moments due to new physics.
We develop a quantum theoretical formalism to derive the brane gravity from its origin -- brane-generating dynamics in higher dimensions. Based on it, we discuss characteristic properties of the brane induced gravity, as well as brane induced field theory.
Assuming naturalness that the quantum corrections to the mass should not exceed the order of the observed mass, we derive and apply model-independent bounds on the anomalous magnetic moments and electric dipole moments of leptons and quarks due to new physics.
We show how the gravity, gauge, and matter fields are induced on dynamically localized brane world.