Statistics of Mesoscopic Fluctuations of Quantum Capacitance

The Thouless formula $G = (e^2/h)(E_c/\Delta)$ for the two-probe dc conductance $G$ of a d-dimensional mesoscopic cube is re-analysed to relate its quantum capacitance $C_Q$ to the reciprocal of the level spacing $\Delta$. To this end, the escape time-scale $\tau$ occurring in the Thouless correlation energy $E_c = \hbar/\tau$ is interpreted as the {\em time constant} $\tau = RC_Q$ with $RG \equiv$ 1, giving at once $C_Q = (e^2/2\pi \Delta)$. Thus, the statistics of the quantum capacitance is directly related to that of the level spacing, which is well known from the Random Matrix Theory for all the three universality classes of statistical ensembles. The basic questions of how intrinsic this quantum capacitance can arise purely quantum-resistively, and of its observability {\em vis-a-vis} the external geometric capacitance that combines with it in series, are discussed

Fractional Power-Law Spectral Response of CaCu3Ti4O12 Dielectric: Many-Body Effects

Spectral character of dielectric response in CaCu3Ti4O12 across 0.5Hz-4MHz over 45-200K corresponding to neither the Debyean nor the KWW relaxation patterns rather indicates a random-walk like diffusive dynamics of moments. Non-linear relaxation here is due to the many body dipole-interactions, as confirmed by spectral-fits of our measured permittivity to the Dissado-Hill behaviour. Fractional power-laws observed in {\epsilon}*({\omega}) macroscopically reflect the fractal microscopic configurations. Below ~100K, the power-law exponent m (n) steeply decreases (increases), indicating finite length-scale collective response of moment-bearing entities. At higher temperatures, m gradually approaches 1 and n falls to low values, reflecting tendency towards the single-particle/Debyean relaxation.Comment: 10 pages, 3 figures, 22 reference

Strings, Junctions and Stability

Identification of string junction states of pure SU(2) Seiberg-Witten theory as B-branes wrapped on a Calabi-Yau manifold in the geometric engineering limit is discussed. The wrapped branes are known to correspond to objects in the bounded derived category of coherent sheaves on the projective line \cp{1} in this limit. We identify the pronged strings with triangles in the underlying triangulated category using Pi-stability. The spiral strings in the weak coupling region are interpreted as certain projective resolutions of the invertible sheaves. We discuss transitions between the spiral strings and junctions using the grade introduced for Pi-stability through the central charges of the corresponding objects.Comment: 15 pages, LaTeX; references added. typos correcte

Lagrangian and Hamiltonian formulations of higher order Chern-Simons theories

We consider models involving the higher (third) derivative extension of the abelian Chern-Simons (CS) topological term in D=2+1 dimensions. The polarisation vectors in these models reveal an identical structure with the corresponding expressions for usual models which contain, at most, quadratic structures. We also investigate the Hamiltonian structure of these models and show how Wigner's little group acts as gauge generator.Comment: 13 pages, Late

An interesting case of suicidal poisoning

Aconite is one of the most poisonous known herbs. It has been known to be used as a homicidal poison from long time in history. However this is rarely known to be used as suicidal poison. Poisoning with aconite is usually fatal and death commonly occurs due to arrhythmias and cardiotoxicity. We report a case of attempted suicidal poisoning by aconite where patient survived in spite of documented cardiotoxic effects of the poison