Gauge field fluctuations and first-order phase transition in color superconductivity.
We study the gauge field fluctuations in dense quark matter and determine the temperature of the induced first-order phase transition to the color-superconducting phase in weak coupling. We find that the local approximation of the coupling between the gauge potential and the order parameter, employed in the Ginzburg-Landau theory, has to be modified by restoring the full momentum dependence of the polarization function of gluons in the superconducting phase.

title: On the Next-leading order Heavy-Quark Potential from AdS/CFT
abstract: Applying the AdS/CFT correspondence, the expansion of the heavy-quark potential of N = 4 supersymmetric Yang–Mills theory at large Nc is carried out to the next-leading term in the large 't Hooft coupling at zero temperature. The strong coupling corresponds to the semi-classical expansion of the string-sigma model, the gravity dual of the Wilson loop operator, with the next-leading term expressed in terms of functional determinants of fluctuations. The singularities of these determinants are examined and their contributions are evaluated numerically. We find the next-leading order correction is negative and suppressed by minus square root of the 't Hooft coupling relative to the leading order.

title: Bosonization of lattice fermions.
abstract: For any purely fermionic system on a lattice in arbitrary space dimension we prove that there is a different but well-defined system on the same lattice, consisting of both [ital bona] [ital fide] fermions and bosons with an interaction depending on a parameter [lambda], which characterizes a same-site repulsion between particles. The energy spectrum and the scattering matrix of the former are identical to those in the finite energy sector of the latter, in the limit [lambda][r arrow][infinity] (i.e., hard-core repulsion). This general theorem is applied to a resonance-boson model in a lattice fermion system, whose solution may have relevance to high-[ital T][sub [ital c]] superconductivity.

title: Multipole expansion of conserved tensor currents and the number of form factors.
abstract: We develop a formalism for defining and studying the form factors which describe the coupling of a spin-{ital J} particle through a conserved tensor current to a spin-{ital S} boson. For {ital S}=2, these form factors are the single-graviton gravitational form factors. We investigate the behavior of the various form factors under {ital C}, {ital P}, {ital T}, and {ital CPT} and classify them accordingly. We show that under {ital CPT} invariance all the multipoles of the mass distribution are the same for a particle and its antiparticle. We also show that in a quantum theory of gravity the coupling of a particle to the graviton is in general different from that of its antiparticle. Only when {ital P} and {ital T} are both valid symmetries of the underlying theory do a particle and its antiparticle couple identically to the graviton. The number of form factors for arbitrary {ital J} and {ital S} is given. We show that a massive Majorana particle (a {ital CPT} self-conjugate particle) coupling to an odd-spin boson possesses only anapole moments. Massless Majorana particles with spin{ne}1/2 have no single-photon electromagnetic form factors while the ones with spin{ne}1/2, 1, or 3/2 have no interactions with amore » spin-3 boson; this applies to the graviton ({ital J}=2, {ital S}=1,3) and to the massless gravitino ({ital J}=3/2, {ital S}=1). Our results also apply to extended objects (nuclei, . . .) in the low-energy limit.« less

title: Electromagnetic properties of generalized Majorana particles.
abstract: We prove a theorem stating that a massive Majorana particle (a CPT-self-conjugate particle) with arbitrary spin J can possess only an anapole moment and multipoles of that. We also show that massless Majorana particles, except those of spin (1/2, do not have any single-photon electromagnetic form factor.

title: Path integrals as discrete sums.
abstract: We present a new formulation of Feynman's path integral, based on Voronin's theorems on the universality of the Riemann zeta function. The result is a discrete sum over paths,'' each given by a zeta function. A new measure which leads to the correct quantum mechanics is explicitly given.

title: Various topics in field theory