Adiabatic Effective Action for Vortices in Neutral and Charged Superfluids

Adiabatic effective action for vortices in neutral and charged superfluids at zero temperature are calculated using the topological Landau-Ginzburg theory recently proposed by Hatsuda, Yahikozawa, Ao and Thouless, and vortex dynamics are examined. The Berry phase term arising in the effective action naturally yields the Magnus force in both neutral and charged superfluids. It is shown that in neutral superfluid there is only one degree of freedom, namely the center of vorticities, and the vortex energy is proportinal to the sum of all vorticities so that it is finite only for the vanishing total vorticity of the system. On the other hand the effective mass and the vortex energy for a vortex in charged superfluids are defined individually as expected. The effects of the vortex core on these quantities are also estimated. The possible depinning scenario which is governed by the Magnus force and the inertial mass is also discussed.Comment: 26 page

Emergent AdS3 and BTZ Black Hole from Weakly Interacting Hot 2d CFT

We investigate emergent holography of weakly coupled two-dimensional hyperK\"ahler sigma model on cotangent bundle of (N-1)-dimensional complex projective space at zero and finite temperature. The sigma model is motivated by the spacetime conformal field theory dual to the near-horizon geometry of Q1 D1-brane bound to Q5 D5-brane wrapped on four-torus times circle, where N = Q1*Q5. The sigma model admits nontrivial instanton for all N greater than or equal to 2, which serves as a local probe of emergent holographic spacetime. We define emergent geometry of the spacetime as that of instanton moduli space via Hitchin's information metric. At zero temperature, we find that emergent geometry is AdS3. At finite temperature, time-periodic instanton is mappable to zero temperature instanton via conformal transformation. Utilizing the transformation, we show that emergent geometry is precisely that of the non-extremal, non-rotating BTZ black hole.Comment: 12 pages, no figure, JHEP.cls; v2. typos correcte

Topological Landau-Ginzburg Theory for Vortices in Superfluid 4^4He

We propose a new Landau-Ginzburg theory for arbitrarily shaped vortex strings in superfluid $^4$He. The theory contains a topological term and directly describes vortex dynamics. We introduce gauge fields in order to remove singularities from the Landau-Ginzburg order parameter of the superfluid, so that two kinds of gauge symmetries appear, making the continuity equation and conservation of the total vorticity manifest. The topological term gives rise to the Berry phase term in the vortex mechanical actions.Comment: LATEX, 9 page

Information metric from a linear sigma model

The idea that a spacetime metric emerges as a Fisher-Rao `information metric' of instanton moduli space has been examined in several field theories such as the Yang-Mills theories and nonlinear sigma models. In this brief paper, we report that the flat Euclidean or Minkowskian metric, rather than an anti-de Sitter metric that generically emerges from instanton moduli spaces, can be obtained as the Fisher-Rao metric from a non-trivial solution of the massive Klein-Gordon field (a linear sigma model). This realization of the flat space from the simple field theory would be useful to investigate the ideas that relate the spacetime geometry with the information geometry.Comment: 8 pages, 1 figure, to appear in PR

Oral administration of live virus protects susceptible mice from developing Theiler's virus-induced demyelinating disease

AbstractIntracerebral infection of susceptible mouse strains with Theiler's murine encephalomyelitis virus (TMEV) results in an immune-mediated demyelinating disease similar to human multiple sclerosis. TMEV infection is widely spread via fecal–oral routes among wild mouse populations, yet these infected mice rarely develop clinical disease. Oral vaccination has often been used to protect the host against many different infectious agents, although the underlying protective mechanism of prior oral exposure is still unknown. To understand the mechanisms involved in protection from demyelinating disease following previous oral infection, immune parameters and disease progression of mice perorally infected with TMEV were compared with those of mice immunized intraperitoneally following intracerebral infection. Mice infected perorally, but not intraperitoneally, prior to CNS viral infection showed lower chronic viral persistence in the CNS and reduced TMEV-induced demyelinating disease. However, a prolonged period of post-oral infection was necessary for effective protection. Mice orally pre-exposed to the virus displayed markedly elevated levels of antibody response to TMEV in the serum, although T cell responses to TMEV in the periphery were not significantly different between perorally and intraperitoneally immunized mice. In addition, orally vaccinated mice showed higher levels of early CNS-infiltration of B cells producing anti-TMEV antibody as well as virus-specific CD4+ and CD8+ T cells in the CNS compared to intraperitoneally immunized mice. Therefore, the generation of a sufficient level of protective immune responses appears to require a prolonged time period to confer protection from TMEV-induced demyelinating disease