Origin of strange metallic phase in cuprate superconductors

The origin of strange metallic phase is shown to exist due to these two conditions---(i) the electrons are strongly interacting such that there are no band and Mott-Hubbard gaps, and (ii) the electronic energy levels are crossed in such a way that there is an electronic energy gap between two energy levels associated to two different wave functions. The theory is also exploited to explain (i) the upward- and downward-shifts in the $T$-linear resistivity curves, and (ii) the spectral weight transfer observed in the soft X-ray absorption spectroscopic measurements of the La-Sr-Cu-O Mott insulator.Comment: To be published in J. Supercond. Nov. Mag

Transverse electrokinetic and microfluidic effects in micro-patterned channels: lubrication analysis for slab geometries

Off-diagonal (transverse) effects in micro-patterned geometries are predicted and analyzed within the general frame of linear response theory, relating applied presure gradient and electric field to flow and electric current. These effects could contribute to the design of pumps, mixers or flow detectors. Shape and charge density modulations are proposed as a means to obtain sizeable transverse effects, as demonstrated by focusing on simple geometries and using the lubrication approximation.Comment: 9 pages, 7 figure

Towards the Theory of Cosmological Phase Transitions

We discuss recent progress (and controversies) in the theory of finite temperature phase transitions. This includes the structure of the effective potential at a finite temperature, the infrared problem in quantum statistics of gauge fields, the theory of formation of critical and subcritical bubbles and the theory of bubble wall propagation.Comment: 50 p

CamouflageFS: Increasing the Effective Key Length in Cryptographic Filesystems on the Cheap

One of the few quantitative metrics used to evaluate the security of a cryptographic file system is the key length of the encryption algorithm; larger key lengths correspond to higher resistance to brute force and other types of attacks. Since accepted cryptographic design principles dictate that larger key lengths also impose higher processing costs, increasing the security of a cryptographic file system also increases the overhead of the underlying cipher. We present a general approach to effectively extend the key length without imposing the concomitant processing overhead. Our scheme is to spread the ciphertext inside an artificially large file that is seemingly filled with random bits according to a key-driven spreading sequence. Our prototype implementation, CamouflageFS, offers improved performance relative to a cipher with a larger key-schedule, while providing the same security properties. We discuss our implementation (based on the Linux Ext2 file system) and present some preliminary performance results. While CamouflageFS is implemented as a stand-alone file system, its primary mechanisms can easily be integrated into existing cryptographic file systems

The (p,t) Reaction at Higher Energy

This work was supported by National Science Foundation Grant PHY 76-84033 and Indiana Universit

On the hyperbolicity and causality of the relativistic Euler system under the kinetic equation of state

We show that a pair of conjectures raised in [11] concerning the construction of normal solutions to the relativistic Boltzmann equation are valid. This ensures that the results in [11] hold for any range of positive temperatures and that the relativistic Euler system under the kinetic equation of state is hyperbolic and the speed of sound cannot overcome $c/\sqrt{3}$.Comment: 6 pages. Abridged version; full version to appear in Commun. Pure Appl. Ana

On the asymptotic spectrum of the reduced volume in cosmological solutions of the Einstein equations

Say S is a compact three-manifold with non-positive Yamabe invariant. We prove that in any long time constant mean curvature Einstein flow over S, having bounded C^{\alpha} space-time curvature at the cosmological scale, the reduced volume (-k/3)^{3}Vol(g(k)) (g(k) is the evolving spatial three-metric and k the mean curvature) decays monotonically towards the volume value of the geometrization in which the cosmologically normalized flow decays. In more basic terms, under the given assumptions, there is volume collapse in the regions where the injectivity radius collapses (i.e. tends to zero) in the long time. We conjecture that under the curvature assumption above the Thurston geometrization is the unique global attractor. We validate it in some special cases.Comment: 25 pages, 2 figure

Operator-Algebraic Approach to the Yrast Spectrum of Weakly Interacting Trapped Bosons

We present an operator-algebraic approach to deriving the low-lying quasi-degenerate spectrum of weakly interacting trapped N bosons with total angular momentum \hbar L for the case of small L/N, demonstrating that the lowest-lying excitation spectrum is given by 27 g n_3(n_3-1)/34, where g is the strength of the repulsive contact interaction and n_3 the number of excited octupole quanta. Our method provides constraints for these quasi-degenerate many-body states and gives higher excitation energies that depend linearly on N.Comment: 7 pages, one figur

Measuring glucose cerebral metabolism in the healthy mouse using hyperpolarized ¹³C magnetic resonance.

The mammalian brain relies primarily on glucose as a fuel to meet its high metabolic demand. Among the various techniques used to study cerebral metabolism, <sup>13</sup> C magnetic resonance spectroscopy (MRS) allows following the fate of <sup>13</sup> C-enriched substrates through metabolic pathways. We herein demonstrate that it is possible to measure cerebral glucose metabolism in vivo with sub-second time resolution using hyperpolarized <sup>13</sup> C MRS. In particular, the dynamic <sup>13</sup> C-labeling of pyruvate and lactate formed from <sup>13</sup> C-glucose was observed in real time. An ad-hoc synthesis to produce [2,3,4,6,6- <sup>2</sup> H <sub>5</sub> , 3,4- <sup>13</sup> C <sub>2</sub> ]-D-glucose was developed to improve the <sup>13</sup> C signal-to-noise ratio as compared to experiments performed following [U- <sup>2</sup> H <sub>7</sub> , U- <sup>13</sup> C]-D-glucose injections. The main advantage of only labeling C3 and C4 positions is the absence of <sup>13</sup> C- <sup>13</sup> C coupling in all downstream metabolic products after glucose is split into 3-carbon intermediates by aldolase. This unique method allows direct detection of glycolysis in vivo in the healthy brain in a noninvasive manner