A Snapshot of Woody Plants Composition in Byram Permanent Mangrove Forest Reserve

The term mangrove may refer to an ecosystem or individual plants where the distribution of woody plants usually influenced by climate, water salinity, tides, type of soil in the mangrove swamps and environmental activities including development, housing and industrial. Thus only a certain species that can survive under this extreme condition. A study had been conducted in Byram Permanent Mangrove Forest Reserve to provide baseline information on the distribution pattern of plant growth in mangrove area. The main objective of this study is to determine the composition and the distribution pattern of true-mangrove woody plant species. To assess the species composition, the forest reserve nearest to the sea, which run approximately 2.0 km, parallel to the sea, was divided into three main sections (i.e. 600 m each section with a minimum 50 m wide border between the sections). Species enumeration was conducted in 11 plots, where each plot size is 10m x 10m. In general these plots were established in random stratified manner, from the sea towards the terrestrial part of the mangrove forest. In total, we recorded 290 of individual woody plants. The most abundant species in term of occurrences within all zones and forest section is Bruguiera parvifolia

Deconstruction, Lattice Supersymmetry, Anomalies and Branes

We study the realization of anomalous Ward identities in deconstructed (latticized) supersymmetric theories. In a deconstructed four-dimensional theory with N=2 supersymmetry, we show that the chiral symmetries only appear in the infrared and that the anomaly is reproduced in the usual framework of lattice perturbation theory with Wilson fermions. We then realize the theory on the world-volume of fractional D-branes on an orbifold. In this brane realization, we show how deconstructed theory anomalies can be computed via classical supergravity. Our methods and observations are more generally applicable to deconstructed/latticized supersymmetric theories in various dimensions.Comment: 1+27 pages, 2 figures, references adde

Supergravity and The Large N Limit of Theories With Sixteen Supercharges

We consider field theories with sixteen supersymmetries, which includes U(N) Yang-Mills theories in various dimensions, and argue that their large N limit is related to certain supergravity solutions. We study this by considering a system of D-branes in string theory and then taking a limit where the brane worldvolume theory decouples from gravity. At the same time we study the corresponding D-brane supergravity solution and argue that we can trust it in certain regions where the curvature (and the effective string coupling, where appropriate) are small. The supergravity solutions typically have several weakly coupled regions and interpolate between different limits of string-M-theory.Comment: 24 pages, latex. v2: reference added, v3: typos correcte

Holographic Thermodynamics at Finite Baryon Density: Some Exact Results

We use the AdS/CFT correspondence to study the thermodynamics of massive N=2 supersymmetric hypermultiplets coupled to N=4 supersymmetric SU(Nc) Yang-Mills theory in the limits of large Nc and large 't Hooft coupling. In particular, we study the theory at finite baryon number density. At zero temperature, we present an exact expression for the hypermultiplets' leading-order contribution to the free energy, and in the supergravity description we clarify which D-brane configuration is appropriate for any given value of the chemical potential. We find a second-order phase transition when the chemical potential equals the mass. At finite temperature, we present an exact expression for the hypermultiplets' leading-order contribution to the free energy at zero mass.Comment: 21 pages, 1 figure; v2 corrected typos, added comments to sections 2.2 and 2.

Cold Nuclear Matter In Holographic QCD

We study the Sakai-Sugimoto model of holographic QCD at zero temperature and finite chemical potential. We find that as the baryon chemical potential is increased above a critical value, there is a phase transition to a nuclear matter phase characterized by a condensate of instantons on the probe D-branes in the string theory dual. As a result of electrostatic interactions between the instantons, this condensate expands towards the UV when the chemical potential is increased, giving a holographic version of the expansion of the Fermi surface. We argue based on properties of instantons that the nuclear matter phase is necessarily inhomogeneous to arbitrarily high density. This suggests an explanation of the "chiral density wave" instability of the quark Fermi surface in large N_c QCD at asymptotically large chemical potential. We study properties of the nuclear matter phase as a function of chemical potential beyond the transition and argue in particular that the model can be used to make a semi-quantitative prediction of the binding energy per nucleon for nuclear matter in ordinary QCD.Comment: 31 pages, LaTeX, 1 figure, v2: some formulae corrected, qualitative results unchange

Orientifolds of Matrix theory and Noncommutative Geometry

We study explicit solutions for orientifolds of Matrix theory compactified on noncommutative torus. As quotients of torus, cylinder, Klein bottle and M\"obius strip are applicable as orientifolds. We calculate the solutions using Connes, Douglas and Schwarz's projective module solution, and investigate twisted gauge bundle on quotient spaces as well. They are Yang-Mills theory on noncommutative torus with proper boundary conditions which define the geometry of the dual space.Comment: 17 pages, LaTeX, minor corrections, two references added, discussions slightly expanded, to appear in Phys. Rev.

One-Loop MHV Amplitudes in Supersymmetric Gauge Theories

Using CSW rules for constructing scalar Feynman diagrams from MHV vertices, we compute the contribution of $\mathcal {N}=1$ chiral multiplet to one-loop MHV gluon amplitude. The result agrees with the one obtained previously using unitarity-based methods, thereby demonstrating the validity of the MHV-diagram technique, in the case of one-loop MHV amplitudes, for all massless supersymmetric theories.Comment: 20 pages, 5 figure

The Chiral Model of Sakai-Sugimoto at Finite Baryon Density

In the context of holographic QCD we analyze Sakai-Sugimoto's chiral model at finite baryon density and zero temperature. The baryon number density is introduced through compact D4 wrapping S^4 at the tip of D8-\bar{D8}. Each baryon acts as a chiral point-like source distributed uniformly over R^3, and leads a non-vanishing U(1)_V potential on the brane. For fixed baryon charge density n_B we analyze the bulk energy density and pressure using the canonical formalism. The baryonic matter with point like sources is always in the spontaneously broken phase of chiral symmetry, whatever the density. The point-like nature of the sources and large N_c cause the matter to be repulsive as all baryon interactions are omega mediated. Through the induced DBI action on D8-\bar{D8}, we study the effects of the fixed baryon charge density n_B on the pion and vector meson masses and couplings. Issues related to vector dominance in matter in the context of holographic QCD are also discussed.Comment: V3: 39 pages, 16 figures, minor corrections, version to appear in JHEP. V2: references added, typos correcte

Notes on Properties of Holographic Matter

Probe branes with finite worldvolume electric flux in the background created by a stack of Dp branes describe holographically strongly interacting fundamental matter at finite density. We identify two quantities whose leading low temperature behavior is independent of the dimensionality of the probe branes: specific heat and DC conductivity. This behavior can be inferred from the dynamics of the fundamental strings which provide a good description of the probe branes in the regime of low temperatures and finite densities. We also comment on the speed of sound on the branes and the temperature dependence of DC conductivity at vanishing charge density.Comment: 18 pages, 2 figures; v2: corrected error in Section 6, conclusions unchanged; v3: improved figures and added clarifying comment

Thermal Correlators in Little String Theory

We calculate, using holographic duality, the thermal two-point function in finite temperature little string theory. The analysis of those correlators reveals possible instabilities of the thermal ensemble, as in previous discussions of the thermodynamics of little string theory. We comment on the dependence of the instability on the spatial volume of the system.Comment: 13 page