according adhar bigdili, muhammad ali was son of abdal biq naqqashbashi (painter laureate)and grandson of aliquli biq jabadar, court painter of shah safi and shah abbas ii safawi. adhar bigdili credited muhammad ali with naqqashbashi of shah tahmasp ii safawi and nadir shah afshar. having learnt the art of painting from his father, muhamma ali in turn trained ali ashraf, who worked under patron...

A parallel algorithm to recognize cographs with a linear processor bound and a log’ II time bound is presented. This result extends the result of Adhar and Peng (1990). Moreover, we get a better time processor product than the algorithm of Lin and Olariu (199 I ). As a consequence distance hereditary graphs can be recognized by the same processor and time bound.

We further study the nonperturbative formulation of two-dimensional black holes. We find a nonlinear differential equation satisfied by the tachyon in the black hole background. We show that singularities in the tachyon field configurations are always associated with divergent semiclassical expansions and are absent in the exact theory. We also discuss how the Euclidian black hole emerges from ...

We describe a real-time classical solution of c = 1 string field theory written in terms of the phase space density, u(p, q, t), of the equivalent fermion theory. The solution corresponds to tunnelling of a single fermion above the filled fermi sea and leads to amplitudes that go as exp(−C/gstr). We discuss how one can use this technique to describe non-perturbative effects in the Marinari-Pari...

We discuss the classical 2-dim. black-hole in the framework of the non-perturbative formulation (in terms of non-relativistic fermions) of c = 1 string field theory. We identify an off-shell operator whose classical equation of motion is that of tachyon in the classical graviton-dilaton black-hole background. The black-hole ‘singularity’ is identified with the fermi surface in the phase space o...

We present a 4-dimensional nonsupersymmetric black hole solution to low energy type IIA string theory which carries D0and D6-brane charges. For equal charges this solution reduces to the one discussed recently by Sheinblatt. We construct the corresponding brane configuration for the extremal case and compute the 1-loop matrix theory potential for the scattering of a 0-brane probe off this brane...

We analyze terms subleading to Rutherford in the S-matrix between black hole and probes of successively high energies. We show that by an appropriate choice of the probe one can read off the quantum state of the black hole from the S-matrix, staying asymptotically far from the BH all the time. We interpret the scattering experiment as scattering off classical stringy backgrounds which explicitl...

We analyse the velocity-dependent potentials seen by D0 and D4-brane probes moving in Type I background for head-on scattering off the fixed planes. We find that at short distances (compared to string length) the D0-brane probe has a nontrivial moduli space metric, in agreement with the prediction of Type I matrix model; however, at large distances it is modified by massive open strings to a fl...

We discuss further a recent space-time interpretation of the c = 1 matrix model which retains both sides of the inverted harmonic oscillator potential in the underlying free fermion theory and reproduces the physics of the discrete state moduli of two-dimensional string theory. We show that within this framework the linear tachyon background in flat space arises from the fermi vacuum. We argue ...

We apply the method of coadjoint orbits of W∞-algebra to the problem of non-relativistic fermions in one dimension. This leads to a geometric formulation of the quantum theory in terms of the quantum phase space distribution of the fermi fluid. The action has an infinite series expansion in the string coupling, which to leading order reduces to the previously discussed geometric action for the ...