Complex and Non-Complex Phase Structures in Models of Spin Glasses and Information Processing

The gauge theory of spin glasses and statistical-mechanical formulation of error-correcting codes are reviewed with an emphasis on their similarities. For the gauge theory, we explain the functional identities on dynamical autocorrelation functions and on the distribution functions of order parameters. These functional identities restrict the possibilities of slow dynamics and complex structure of the phase space. An inequality for error-correcting codes is shown to be interpreted to indicate non-monotonicity of spin orientation as a function of the temperature in spin glasses.Comment: 13 pages; Proceedings of the International Symposium on Slow Dynamics in Nature, Seoul, Korea, November 2001; to be published in Physica

Torsion points of abelian varieties with values in infinite extensions over a p-adic field

Let $A$ be an abelian variety over a $p$-adic field $K$ and $L$ an algebraic infinite extension over $K$. We consider the finiteness of the torsion part of the group of rational points $A(L)$ under some assumptions. In 1975, Hideo Imai proved that such a group is finite if $A$ has good reduction and $L$ is the cyclotomic $\mathbb{Z}_p$-extension of $K$. In this talk, first we show a generalization of Imai's result in the case where $A$ has ordinary good reduction. Next we give some finiteness results when $A$ is an elliptic curve and $L$ is the field generated by the $p$-power torsion of an elliptic curve

Four-Dimensional Planck Scale is Not Universal in Fifth Dimension in Randall-Sundrum Scenario

It has recently been proposed that the hierarchy problem can be solved by considering the warped fifth dimension compactified on $S^{1}/Z_{2}$. Many studies in the context have assumed a particular choice for an integration constant $\sigma_{0}$ that appears when one solves the five-dimensional Einstein equation. Since $\sigma_{0}$ is not determined by the boundary condition of the five-dimensional theory, $\sigma_{0}$ may be regarded as a gauge degree of freedom in a sense. To this time, all indications are that the four-dimensional Planck mass depends on $\sigma_{0}$. In this paper, we carefully investigate the properties of the geometry in the Randall-Sundrum model, and consider in which location $y$ the four-dimensional Planck mass is measured. As a result, we find a $\sigma_{0}$-independent relation between the four-dimensional Planck mass $M_{\rm Pl}$ and five- dimensional fundamental mass scale $M$, and remarkably enough, we can take $M$ to TeV region when we consider models with the Standard Model confined on a distant brane. We also confirm that the physical masses on the distant brane do not depend on $\sigma_{0}$ by considering a bulk scalar field as an illustrative example. The resulting mass scale of the Kaluza-Klein modes is on the order of $M$.Comment: Latex, 12 page