A No-Go Theorem for M5-brane Theory

The BLG model for multiple M2-branes motivates an M5-brane theory with a novel gauge symmetry defined by the Nambu-Poisson structure. This Nambu-Poisson gauge symmetry for an M5-brane in large C-field background can be matched, on double dimension reduction, with the Poisson limit of the noncommutative gauge symmetry for a D4-brane in B-field background. Naively, one expects that there should exist a certain deformation of the Nambu-Poisson structure to match with the full noncommutative gauge symmetry including higher order terms. However, We prove the no-go theorem that there is no way to deform the Nambu-Poisson gauge symmetry, even without assuming the existence of a deformation of Nambu-Poisson bracket, to match with the noncommutative gauge symmetry in 4+1 dimensions to all order, regardless of how the double dimension reduction is implemented.Comment: v4: minor modifications

Effect of Hepatitis-B Virus Co-Infection on CD4 Cell Count and Liver Function of HIV Infected Patients

Background: Human immunodeficiency virus (HIV) and Hepatitis B virus (HBV) share similar routes of transmission, making it possible for an individual to have a co-infection. HBV infection is well known to be a major cause of chronic liver diseases worldwide. The aim of this study was to determine the prevalence of HBV infection among HIV infected HAART naïve patients and investigate the effect of co-infection on CD4 count and liver function.Study design: This was a hospital based descriptive cross sectional study of one hundred consecutive therapy- naive HIV-infected individuals. The CD4 count, Hepatitis B surface antigen, Serum albumin, total Protein, and liver  enzymes were determined using standard techniques.Results: The prevalence of HIV and HBV co-infection was 37%. The mean serum ALT and ALP were significantly higher in the co- infected patients (P-values <0.05). The mean CD4 count of the mono infected patients was significantly higher (p-value of 0.014). The mean serum ALT, AST and ALP of mono and coinfected patients with CD4 count<200/μl were significantly higher than those with count ≥ 200 cells/μl. (pvalue of <0.01). The mean ALT and  AST of the co - infected patients and all patients with CD4 count <200 cells/μl were higher than the normal reference range.Conclusion: Approximately one third of HIV positive patients had hepatitis B virus co-infection. Coinfection and CD4 count <200 cells/μl are likely to result in abnormal ALT and AST. We recommend those co-infected patients and those with CD4 count <200 cells/μl should be given non-hepatotoxic antiretroviral drug.Keywords: HIV, Hepatitis B, CD4 count, liver function, co-infectio

BPS States on M5-brane in Large C-field Background

We extensively study BPS solutions of the low energy effective theory of M5-brane in large C-field background. This provides us an opportunity to explore the interactions turned on by C-field background through the Nambu-Poisson structure. The BPS states considered in this paper include the M-waves, the self-dual string (M2 ending on M5), tilted M5-brane, holomorphic embedding of M5-brane and the intersection of two M5-branes along a 3-brane.Comment: 25 pages, reference adde

A Non-Abelian Self-Dual Gauge Theory in 5+1 Dimensions

We construct a non-Abelian gauge theory of chiral 2-forms (self-dual gauge fields) in 6 dimensions with a spatial direction compactified on a circle of radius R. It has the following two properties. (1) It reduces to the Yang-Mills theory in 5 dimensions for small R. (2) It is equivalent to the Lorentz-invariant theory of Abelian chiral 2-forms when the gauge group is Abelian. Previous no-go theorems prohibiting non-Abelian deformations of the chiral 2-form gauge theory are circumvented by introducing nonlocality along the compactified dimension.Comment: 23 pages, reference adde

Dp-branes, NS5-branes and U-duality from nonabelian (2,0) theory with Lie 3-algebra

We derive the super Yang-Mills action of Dp-branes on a torus T^{p-4} from the nonabelian (2,0) theory with Lie 3-algebra. Our realization is based on Lie 3-algebra with pairs of Lorentzian metric generators. The resultant theory then has negative norm modes, but it results in a unitary theory by setting VEV's of these modes. This procedure corresponds to the torus compactification, therefore by taking a transformation which is equivalent to T-duality, the Dp-brane action is obtained. We also study type IIA/IIB NS5-brane and Kaluza-Klein monopole systems by taking other VEV assignments. Such various compactifications can be realized in the nonabelian (2,0) theory, since both longitudinal and transverse directions can be compactified, which is different from the BLG theory. We finally discuss U-duality among these branes, and show that most of the moduli parameters in U-duality group are recovered. Especially in D5-brane case, the whole U-duality relation is properly reproduced.Comment: 1+26 page

Ultracold Gases of Ytterbium: Ferromagnetism and Mott States in an SU(6) Fermi System

It is argued that ultracold quantum degenerate gas of ytterbium $^{173}$Yb atoms having nuclear spin $I = 5/2$ exhibits an enlarged SU$(6)$ symmetry. Within the Landau Fermi liquid theory, stability criteria against Fermi liquid (Pomeranchuk) instabilities in the spin channel are considered. Focusing on the SU$(n > 2)$ generalizations of ferromagnetism, it is shown within mean-field theory that the transition from the paramagnet to the itinerant ferromagnet is generically first order. On symmetry grounds, general SU$(n)$ itinerant ferromagnetic ground states and their topological excitations are also discussed. These SU$(n > 2)$ ferromagnets can become stable by increasing the scattering length using optical methods or in an optical lattice. However, in an optical lattice at current experimental temperatures, Mott states with different filling are expected to coexist in the same trap, as obtained from a calculation based on the SU$(6)$ Hubbard model.Comment: 4+ pages, 1 figure; v2: Improved discussion of the SU(6) symmetry-breaking patterns; v3: added further discussion on the order of the transition. Added Reference

More on the Nambu-Poisson M5-brane Theory: Scaling limit, background independence and an all order solution to the Seiberg-Witten map

We continue our investigation on the Nambu-Poisson description of M5-brane in a large constant C-field background (NP M5-brane theory) constructed in Refs.[1, 2]. In this paper, the low energy limit where the NP M5-brane theory is applicable is clarified. The background independence of the NP M5-brane theory is made manifest using the variables in the BLG model of multiple M2-branes. An all order solution to the Seiberg-Witten map is also constructed.Comment: expanded explanations, minor corrections and typos correcte

Nonabelian (2,0) Tensor Multiplets and 3-algebras

Using 3-algebras we obtain a nonabelian system of equations that furnish a representation of the (2,0)-supersymmetric tensor multiplet. The on-shell conditions are quite restrictive so that the system can be reduced to five-dimensional gauge theory along with six-dimensional abelian (2,0) tensor multiplets. We briefly discuss possible applications to D4-branes using a spacelike reduction and M5-branes using a null reduction.Comment: 17 pages, Latex; v2: Typos corrected and references adde

Dental restorations for oral rehabilitation – testing of laboratory properties versus clinical performance for clinical decision making *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73116/1/j.1365-2842.2007.01812.x.pd

Non-abelian Action for Multiple Five-Branes with Self-Dual Tensors

We construct an action for non-abelian 2-form in 6-dimensions. Our action consists of a non-abelian generalization of the abelian action of Perry and Schwarz for a single five-brane. It admits a self-duality equation on the field strength as the equation of motion. It has a modified 6d Lorentz symmetry. On dimensional reduction on a circle, our action gives the standard 5d Yang-Mills action plus higher order corrections. Based on these properties, we propose that our theory describes the gauge sector of multiple M5-branes in flat space.Comment: LaTeX, 26 pages. v2: improved discussion of Lorentz symmetry. ref added. v3: add comments in the discussion section on the inclusion of scalar fields and supersymmetry; title changed to a more suitable one; version published in JHE