Thermodynamic Properties of Small Localized Black Holes

In a previous paper, we developed a numerical method to obtain a static black hole localized on a 3-brane in the Randall-Sundrum infinite braneworld, and presented examples of numerical solutions that describe small localized black holes. In this paper we quantitatively analyze the behavior of the numerically obtained black hole solutions, focusing on thermodynamic quantities. The thermodynamic relations show that the localized black hole deviates smoothly from a five-dimensional Schwarzschild black hole, which is a solution in the limit of a small horizon radius. We compare the thermodynamic behavior of these solutions with that of the exact solution on the 2-brane in the 4D braneworld. We find similarities between them.Comment: 6 pages, 6 figures, RevTex, references adde

Money and price dynamics in a market with strategic bargaining

This paper studies a strategic bargaining model of money and prices to complement the results reported in Coles and Wright (1998). The probability of a bargaining breakdown is chosen to be consistent with market conditions in the spirit of Rubinstein and Wolinsky (1985). The unique monetary steady state coincides with the one under asymmetric Nash bargaining. The dynamics of the price level are determined without any reference to the value of search. The dynamic properties of the model resemble those of traditional monetary models.money, bargaining, price dynamics.

A global analysis of liquidity effects, interest rate rules, and deflationary traps

The prevailing models of liquidity traps suggest that a deflationary trap is a stable steady state in a multiple equilibria model. These models implicitly assume that the central bank accelerates the process of disinflation by following a Taylor rule even though there is a long run positive relationship between the nominal interest rate and inflation rate. This paper presents a reduced-form model that integrates liquidity effects into the analysis of interest rate rules to generalize the previous results about uniqueness, determinacy, and dynamic property of the economy.Taylor rules, liquidity effects, liquidity traps, deflation.

Induced Core Formation Time in Subcritical Magnetic Clouds by Large-Scale Trans-Alfv\'enic Flows

We clarify the mechanism of accelerated core formation by large-scale nonlinear flows in subcritical magnetic clouds by finding a semi-analytical formula for the core formation time and describing the physical processes that lead to them. Recent numerical simulations show that nonlinear flows induce rapid ambipolar diffusion that leads to localized supercritical regions that can collapse. Here, we employ non-ideal magnetohydrodynamic simulations including ambipolar diffusion for gravitationally stratified sheets threaded by vertical magnetic fields. One of the horizontal dimensions is eliminated, resulting in a simpler two-dimensional simulation that can clarify the basic process of accelerated core formation. A parameter study of simulations shows that the core formation time is inversely proportional to the square of the flow speed when the flow speed is greater than the Alfv\'en speed. We find a semi-analytical formula that explains this numerical result. The formula also predicts that the core formation time is about three times shorter than that with no turbulence, when the turbulent speed is comparable to the Alfv\'en speed.Comment: 22 pages, 9 figures, accepted for publication in Ap

Properties of Kaluza-Klein black holes

We detail numerical methods to compute the geometry of static vacuum black holes in 6 dimensional gravity compactified on a circle. We calculate properties of these Kaluza-Klein black holes for varying mass, while keeping the asymptotic compactification radius fixed. For increasing mass the horizon deforms to a prolate ellipsoid, and the geometry near the horizon and axis decompactifies. We are able to find solutions with horizon radii approximately equal to the asymptotic compactification radius. Having chosen 6-dimensions, we may compare these solutions to the non-uniform strings compactified on the same radius of circle found in previous numerical work. We find the black holes achieve larger masses and horizon volumes than the most non-uniform strings. This sheds doubt on whether these solution branches can merge via a topology changing solution. Further work is required to resolve whether there is a maximum mass for the black holes, or whether the mass can become arbitrarily large.Comment: 33 pages, 13 colour figures; v2 minor corrections and some figures beautifie

Second order perturbations in the radius stabilized Randall-Sundrum two branes model II -- Effect of relaxing strong coupling approximation --

We discuss gravitational perturbations in the Randall-Sundrum two branes model with radius stabilization. Following the idea by Goldberger and Wise for the radius stabilization, we introduce a scalar field which has potentials localized on the branes in addition to a bulk potential. In our previous paper we discussed gravitational perturbations induced by static, spherically symmetric and nonrelativistic matter distribution on the branes under the condition that the values of the scalar field on the respective branes cannot fluctuate due to its extremely narrow brane potentials. We call this case the strong coupling limit. Our concern in this paper is to generalize our previous analysis relaxing the limitation of taking the strong coupling limit. We find that new corrections in metric perturbations due to relaxing the strong coupling limit enhance the deviation from the 4D Einstein gravity only in some exceptional cases. In the case that matter fields reside on the negative tension brane, the stabilized radion mass becomes very small when the new correction becomes large.Comment: 12 pages, No figures, typos correcte

Doubly Spinning Black Rings

We study a method to solve stationary axisymmetric vacuum Einstein equations numerically. As an illustration, the five-dimensional doubly spinning black rings that have two independent angular momenta are formulated in a way suitable for fully nonlinear numerical method. Expanding for small second angular velocity, the formulation is solved perturbatively upto second order involving the backreaction from the second spin. The obtained solutions are regular without conical singularity, and the physical properties are discussed with the phase diagram of the reduced entropy vs the reduced angular momenta. Possible extensions of the present approach to constructing the higher dimensional version of black ring and the ring with the cosmological constant are also discussed.Comment: 20 pages, 6 figure

Optimal supply against fluctuating demand

Sornette et al. claimed that the optimal supply does not agree with the average demand, by analyzing a bakery model where a daily demand fluctuates with a uniform distribution. In this note, we extend the model to general probability distributions, and obtain the formula of the optimal supply for Gaussian distribution, which is more realistic. Our result is useful in a real market to earn the largest income on average.Comment: 2 page

Probing anisotropies of gravitational-wave backgrounds with a space-based interferometer: geometric properties of antenna patterns and their angular power

We discuss the sensitivity to anisotropies of stochastic gravitational-wave backgrounds (GWBs) observed via space-based interferometer. In addition to the unresolved galactic binaries as the most promising GWB source of the planned Laser Interferometer Space Antenna (LISA), the extragalactic sources for GWBs might be detected in the future space missions. The anisotropies of the GWBs thus play a crucial role to discriminate various components of the GWBs. We study general features of antenna pattern sensitivity to the anisotropies of GWBs beyond the low-frequency approximation. We show that the sensitivity of space-based interferometer to GWBs is severely restricted by the data combinations and the symmetries of the detector configuration. The spherical harmonic analysis of the antenna pattern functions reveals that the angular power of the detector response increases with frequency and the detectable multipole moments with effective sensitivity h_{eff} \sim 10^{-20} Hz^{-1/2} may reach $\ell \sim$ 8-10 at $f \sim f_*=10$ mHz in the case of the single LISA detector. However, the cross correlation of optimal interferometric variables is blind to the monopole (\ell=0) intensity anisotropy, and also to the dipole (\ell=1) in some case, irrespective of the frequency band. Besides, all the self-correlated signals are shown to be blind to the odd multipole moments (\ell=odd), independently of the frequency band.Comment: RevTex4, 22 pages, 6 figures (low resolution), typos correcte