Plasma balls/kinks as solitons of large NN confining gauge theories

We discuss finite regions of the deconfining phase of a confining gauge theory (plasma balls/kinks) as solitons of the large $N$, long wavelength, effective Lagrangian of the thermal gauge theory expressed in terms of suitable order parameters. We consider a class of confining gauge theories whose effective Lagrangian turns out to be a generic 1 dim. unitary matrix model. The dynamics of this matrix model can be studied by an exact mapping to a non-relativistic many fermion problem on a circle. We present an approximate solution to the equations of motion which corresponds to the motion (in Euclidean time) of the Fermi surface interpolating between the phase where the fermions are uniformly distributed on the circle (confinement phase) and the phase where the fermion distribution has a gap on the circle (deconfinement phase). We later self-consistently verify that the approximation is a good one. We discuss some properties and implications of the solution including the surface tension which turns out to be positive. As a by product of our investigation we point out the problem of obtaining time dependent solutions in the collective field theory formalism due to generic shock formation.Comment: 26+1 pages, 10 figure

Blackhole/String Transition for the Small Schwarzschild Blackhole of AdS5×S5AdS_5 \times S^5 and Critical Unitary Matrix Models

In this paper we discuss the blackhole-string transition of the small Schwarzschild blackhole of $AdS_5 \times S^5$ using the AdS/CFT correspondence at finite temperature. The finite temperature gauge theory effective action, at weak {\it and} strong coupling, can be expressed entirely in terms of constant Polyakov lines which are $SU (N)$ matrices. In showing this we have taken into account that there are no Nambu-Goldstone modes associated with the fact that the 10 dimensional blackhole solution sits at a point in $S^5$. We show that the phase of the gauge theory in which the eigenvalue spectrum has a gap corresponds to supergravity saddle points in the bulk theory. We identify the third order $N = \infty$ phase transition with the blackhole-string transition. This singularity can be resolved using a double scaling limit in the transition region where the large N expansion is organized in terms of powers of $N^{-2/3}$. The $N = \infty$ transition now becomes a smooth crossover in terms of a renormalized string coupling constant, reflecting the physics of large but finite N. Multiply wound Polyakov lines condense in the crossover region. We also discuss the implications of our results for the resolution of the singularity of the Lorenztian section of the small Schwarzschild blackhole.Comment: 44 pages, Minor changes,the submitted version in the journa

Room temperature giant baroresistance and magnetoresistance and its tunability in Pd doped FeRh

We report room temperature giant baro-resistance ($\approx$128\%) in $Fe_{49}(Rh_{0.93}Pd_{0.07})_{51}$. With the application of external pressure and magnetic field the temperature range of giant baro-resistance ($\approx$600\% at 5K and 19.9 kbar and 8 Tesla) and magnetoresistance ($\approx$-85\% at 5K and 8 tesla) can be tuned from 5 K to well above room temperature. As the AFM state is stabilized at room temperature under external pressure, it shows giant room temperature magnetoresistance ($\approx$-55\%) with magnetic field. Due to coupled magnetic and latticel changes, the isothermal change in room temperature resistivity with pressure (in the absence of applied magnetic field) as well as magnetic field (under various constant pressure) can be scaled together to a single curve when plotted as a function of X = T + 12.8*H - 7.2*P

R-charged AdS_{5} black holes and large N unitary matrix models

Using the AdS/CFT, we establish a correspondence between the intricate thermal phases of R-charged AdS_{5} blackholes and the R-charge sector of the N=4 gauge theory, in the large N limit. Integrating out all fields in the gauge theory except the thermal Polyakov line, leads to an effective unitary matrix model. In the canonical ensemble, a logarithmic term is generated in the non-zero charge sector of the matrix model. This term is important to discuss various supergravity properties like i) the non-existence of thermal AdS as a solution, ii) the existence of a point of cusp catastrophe in the phase diagram and iii) the matching of saddle points and the critical exponents of supergravity and those of the effective matrix model.Comment: 24 pages, 5 figure