Chiral rings, Mirror Symmetry and the Fate of Localized Tachyons

The paper is withdrawn by the author. Parts of the contents are expanded into separate papers; hep-th/0308015 LOCALIZED TACHYON MASS AND A G-THEOREM ANALOGUE, hep-th/0308028 COMMENTS ON THE FATE OF UNSTABLE ORBIFOLDS, hep-th/0308029 CHIRAL RINGS AND GSO PROJECTION IN ORBIFOLDS.Comment: withdrawn by the autho

Holographic Wilsonian RG Flow and Sliding Membrane Paradigm

We study the relations between two different approaches to the holographic Renormalization Group (RG) flow at the dual gravity level: One is the radial evolution of the classical equation of motion and the other is the flow equation given by the holographic Wilsonian RG coming from the cut off independence. Apparently, the two flows look different. We give general proofs that the two flows are actually equivalent. The role of the momentum continuity (MC) is essential. We show that MC together with cutoff independence gives the evolution equation of the boundary values. Equivalence of conductivity flows in two paradigm has been shown as an explicit example. We also get the connecting formula of Green functions and AC conductivity at arbitrary slice in terms of its value at horizon for various geometry backgrounds.Comment: 21pages, 9 figures, published version, minor change

Chiral rings and GSO projection in Orbifolds

The GSO projection in the twisted sector of orbifold background is sometimes subtle and incompatible descriptions are found in literatures. Here, from the equivalence of partition functions in NSR and GS formalisms, we give a simple rule of GSO projection for the chiral rings of string theory in \C^r/\Z_n, $r=1,2,3$. Necessary constructions of chiral rings are given by explicit mode analysis.Comment: 24 page

Holographic dual of Cold Trapped Fermions

We study cold fermionic atoms using the holographic principle. We note that current atomic experiments with massive fermions trapped in a harmonic potential in the unitarity limit behave as massless fermions thanks to the Thomas-Fermi approximation. We map the thermodynamics of strongly correlated massless fermion to that of the charged black hole and study the thermodynamics and transport properties of cold fermions at strong coupling at finite temperature and density. In cold limit, the specific heat of charged black hole is linear in $T$ independent of the dimensionality, which is reminiscent of Fermi liquids. The shear viscosity per particle is shown to be finite as a consequence of the non-vanishing of the entropy. We show that our holographic results compare favorably with most of the current atomic data.Comment: 22 page latex, v2:reference added, sec.7's title change. v3) c_V recalculated, v4)C_V T in all dimension is stressed v5) a version to be accepted in jhe