http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2012, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2012/726030/This paper is dedicated to the amazing Kawai-Lewellen-Tye relations, connecting perturbative gravity and gauge theories at tree level. The main focus is on n-point derivations and general properties both from a string theory and pure field theory point of view. In particular, the field theory part is based on some very recent developments.Thomas SøndergaardCopyright © 2012 Thomas Søndergaard. All rights reserved.http://www.hindawi.com/journals/ahep/2011/123184/We review the holographic multiquark states in the deconfined quark-gluon plasma. Nuclear matter can become deconfined by extremely high temperature and/or density. In the deconfined nuclear medium, bound states with colour degrees of freedom are allowed to exist. Using holographic approach, the binding energy and the screening length of the multiquarks can be calculated. Using the deconfined Sakai-Sugimoto model, the phase diagram of the multiquark phase, the vacuum phase, and the chiral-symmetric quark-gluon plasma can be obtained. Then we review the magnetic properties of the multiquarks and their phase diagrams. The multiquark phase is compared with the pure pion gradient, the magnetized vacuum, and the chiral-symmetric quark-gluon plasma phases. For moderate temperature and sufficiently large density at a fixed magnetic field, the mixed phase of multiquark and pion gradient is the most energetically preferred phase.Piyabut Burikham and Ekapong HirunsirisawatCopyright © 2011 Piyabut Burikham and Ekapong Hirunsirisawat. All rights reserved.http://www.hindawi.com/journals/ahep/2011/259025/The purpose of this review is to provide basic ingredients of holographic QCD to nonexperts in string theory and to summarize its interesting achievements in nuclear and hadron physics. We focus on results from a less stringy bottom-up approach and review a stringy top-down model with some calculational details.Youngman Kim and Deokhyun YiCopyright © 2011 Youngman Kim and Deokhyun Yi. All rights reserved.http://www.hindawi.com/journals/ahep/2011/593423/We offer an interpretation of superquantum correlations in terms of a “doubly” quantum theory. We argue that string theory, viewed as a quantum theory with two deformation parameters, the string tension α', and the string coupling constant gs, is such a superquantum theory that transgresses the usual quantum violations of Bell's inequalities. We also discuss the ℏ→∞ limit of quantum mechanics in this context. As a superquantum theory, string theory should display distinct experimentally observable supercorrelations of entangled stringy states.Lay Nam Chang, Zachary Lewis, Djordje Minic, Tatsu Takeuchi, and Chia-Hsiung TzeCopyright © 2011 Lay Nam Chang et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/190587/A number of features and applications of subleading-color amplitudes of N=4 SYM theory are reviewed. Particular attention is given to the IR divergences of the subleading-color amplitudes, the relationships of N=4 SYM theory to N=8 supergravity, and to geometric interpretations of one-loop subleading-color and NkMHV amplitudes of N=4 SYM theory.Stephen G. Naculich, Horatiu Nastase, and Howard J. SchnitzerCopyright © 2011 Stephen G. Naculich et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/649828/This paper presents the results of experimental investigations into the current-voltage characteristics of a planar diode with an explosive emission cathode made from graphite. Studies were performed using a TEU-500 pulsed electron accelerator (350–500 keV, 100 ns, 250 J per pulse). Duration of diode operation, in a mode when electron current is limited by the emissive ability of the graphite cathode, is 15–20 ns. The contribution of the cathode periphery to total electron current appears only as an increase in the emissive surface area due to an expansion of explosive plasma. Investigations of an ion diode with a graphite cathode (plane and focusing geometry) were also carried out. Experiments were performed using a TEMP-4M ion accelerator, which forms two nanosecond pulses: the first negative pulse (150–200 kV, 300–600 ns) followed by the second positive (250–300 kV, 150 ns). Total diode current in the first pulse is well described by the Child-Langmuir law for electron current at a constant rate of plasma expansion, equal to 1.3 cm/μs. It is shown that for an area of flat cathode over 25 cm2, the influence of edge contribution does not exceed measurement error of total diode electron current (10%).Yulia I. Isakova, Galina E. Kholodnaya, and Alexander I. PushkarevCopyright © 2011 Yulia I. Isakova et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/472718/We consider the realization of 2-dimensional Galilean conformal algebra (GCA2) on the boundary of cosmological new massive gravity. At first, we consider the contracted BTZ black hole solution. We obtain entropy formula for the GCA2 in terms of contracted scaling dimension Δ and central charge C1. This entropy formula exactly matches with the nonrelativistic limit of Bekenstein-Hawking entropy of BTZ black hole. Then, we extend our study to the contracted warped AdS3 black hole solution of CNMG. We obtain the entropy of dual GCA2 in terms of central charges and finite temperatures, T1, T2. Again, this expression coincides with the nonrelativistic limit of Bekenstein-Hawking entropy formula of warped AdS3 black hole.M. R. Setare and V. KamaliCopyright © 2011 M. R. Setare and V. Kamali. All rights reserved.http://www.hindawi.com/journals/ahep/2011/468549/We discuss a comprehensive description of the geometry of the brane-world cosmologies, and present bulk and brane structure and matching between brane and bulk metrics. It is clear that the possibility of the matching condition is not always obvious and therefore it requires a separate analysis. In this study we have shown, under the assumption of consideration of the anisotropic metric except Kasner-AdS like, matching procedure is not achieved for Bianchi-types bulk metrics. Examples of this result are presented by the illustrations of the Bianchi-types II and V bulk metrics.O. Sevinc and E. GudekliCopyright © 2011 O. Sevinc and E. Gudekli. All rights reserved.http://www.hindawi.com/journals/ahep/2011/458087/Approximate solutions of the D-dimensional Klein-Gordon equation are obtained for the scalar and vector general Kratzer potential for any l by using the ansatz method. The energy behavior is numerically discussed.H. Hassanabadi, H. Rahimov, and S. ZarrinkamarCopyright © 2011 H. Hassanabadi et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/859762/New Abelian vector bosons can kinetically mix with the hypercharge gauge boson of the Standard Model. This letter computes the model-independent limits on vector bosons with masses from 1 GeV to 1 TeV. The limits arise from the numerous e+e− experiments that have been performed in this energy range and bound the kinetic mixing by ϵ≲0.03 for most of the mass range studied, regardless of any additional interactions that the new vector boson may have.Anson Hook, Eder Izaguirre, and Jay G. WackerCopyright © 2011 Anson Hook et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/917127/Focusing on the connection between the Landau theory of second-order phase transitions and the holographic approach to critical phenomena, we study diverse field theories in an anti de Sitter black hole background. Through simple analytical approximations, solutions to the equations of motion can be obtained in closed form which give rather good approximations of the results obtained using more involved numerical methods. The agreement we find stems from rather elementary considerations on perturbation of Schrödinger equations.Marc Bellon, Enrique F. Moreno, and Fidel A. SchaposnikCopyright © 2011 Marc Bellon et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/241419/I generalize the deconstruction lattice formulation of Endres and Kaplan to two-dimensional super-QCD with eight supercharges, denoted by (4,4), and bifundamental matter. I specialize to a particularly interesting (4,4) gauge theory, with gauge group U(Nc)×U(Nf), and U(Nf) being weakly gauged. It describes the infrared limit of the D1/D5 brane system, which has been studied extensively as an example of the AdS3/CFT2 correspondence. The construction here preserves two supercharges exactly and has a lattice structure quite similar to that which has previously appeared in the deconstruction approach, that is, site, link, and diagonal fields with both the Bose and Fermi statistics. I remark on possible applications of the lattice theory that would test the AdS3/CFT2 correspondence, particularly one that would exploit the recent worldsheet instanton analysis of Chen and Tong.Joel GiedtCopyright © 2011 Joel Giedt. All rights reserved.http://www.hindawi.com/journals/ahep/2011/709492/Theories of dark matter that support bound states are an intriguing possibility for the identity of the missing mass of the Universe. This article proposes a class of models of supersymmetric composite dark matter where the interactions with the Standard Model communicate supersymmetry breaking to the dark sector. In these models, supersymmetry breaking can be treated as a perturbation on the spectrum of bound states. Using a general formalism, the spectrum with leading supersymmetry effects is computed without specifying the details of the binding dynamics. The interactions of the composite states with the Standard Model are computed, and several benchmark models are described. General features of nonrelativistic supersymmetric bound states are emphasized.Siavosh R. Behbahani, Martin Jankowiak, Tomas Rube, and Jay G. WackerCopyright © 2011 Siavosh R. Behbahani et al. All rights reserved.http://www.hindawi.com/journals/ahep/2011/975237/We study the decay of a Z′-boson into U-unparticle and a photon. The extended Landau-Yang theorem is used. The clear photon signal would make the decay Z′→γU as an additional contribution mode for study of unparticle physics.G. A. Kozlov and I. N. GorbunovCopyright © 2011 G. A. Kozlov and I. N. Gorbunov. All rights reserved.http://www.hindawi.com/journals/ahep/2010/120964/A global approach with cutoff exponential functions is used to obtain the Casimir energy of a massless scalar field in the presence of a spherical shell. The proposed method, mathematically well defined at the outset, makes use of two regulators, one of them to make the sum of the orders of Bessel functions finite and the other to regularize the integral involving the zeros of Bessel function. This procedure ensures a consistent mathematical handling in the calculations of the Casimir energy and allows a major comprehension on the regularization process when nontrivial symmetries are under consideration. In particular, we determine the Casimir energy of a scalar field, showing all kinds of divergences. We consider separately the contributions of the inner and outer regions of a spherical shell and show that the results obtained are in agreement with those known in the literature, and this gives a confirmation for the consistence of the proposed approach. The choice of the scalar field was due to its simplicity in terms of physical quantity spin.M. S. R. Miltão and Franz A. FariasCopyright © 2010 M. S. R. Miltão and Franz A. Farias. All rights reserved.http://www.hindawi.com/journals/ahep/2010/768054/The study of the condensation of monopoles and the resulting chromomagnetic superconductivity have been undertaken in restricted chromodynamics of SU(2) gauge theory. Constructing the RCD Lagrangian and the partition function for monopoles in terms of string action and the action of the current around the strings, the monopole current in RCD chromo magnetic superconductor has been derived and it has shown that in London' limit the penetration length governs the monopole density around RCD string in chromo magnetic superconductors while with finite (nonzero) coherence length the leading behavior of the monopole density at large distances from the string is controlled by the coherence length and not by the penetration length.B. S. Rajput and Sandeep KumarCopyright © 2010 B. S. Rajput and Sandeep Kumar. All rights reserved.http://www.hindawi.com/journals/ahep/2010/713659/Constructing the effective action for dyonic field in Abelian projection of QCD, it has been demonstrated that any charge (electrical or magnetic) of dyon screens its own direct potential to which it minimally couples and antiscreens the dual potential leading to dual superconductivity in accordance with generalized Meissner effect. Taking the Abelian projection of QCD, an Abelian Higgs model, incorporating dual superconductivity and confinement, has been constructed and its representation has been obtained in terms of average of Wilson loop.B. S. Rajput and Sandeep KumarCopyright © 2010 B. S. Rajput and Sandeep Kumar. All rights reserved.http://www.hindawi.com/journals/ahep/2010/379473/We have shown that the fourth component of Einstein's complex for the Kantowski-Sachs space-time is not identically zero. We have calculated the total energy of this space-time by using the energy-momentum definitions of Møller in the theory of general relativity and the tetrad theory of gravity.M. Abdel-Megied and Ragab M. GadCopyright © 2010 M. Abdel-Megied and Ragab M. Gad. All rights reserved.http://www.hindawi.com/journals/ahep/2009/873051/Confinement in QCD results from special properties of vacuum fluctuations of gluon fields. There are two numerically different scales, characterizing nonperturbative QCD vacuum dynamics: “small” one, corresponding to gluon condensate, critical temperature etc, which is about 0.1–0.3 GeV, and a “large” one, given by inverse confining string width, glueball and gluelump masses, and so forth, which is about 1.5–2.5 GeV. We discuss the origin of this hierarchy in a picture where confinement is ensured by quadratic colorelectric field correlators of the special type. These correlators, on the other hand, can be calculated via gluelump Green's function, whose dynamics is defined by the correlators themselves. In this way one obtains a self-consistent scheme, where string tension can be expressed in terms of ΛQCD.Yu. A. Simonov and V. I. ShevchenkoCopyright © 2009 Yu. A. Simonov and V. I. Shevchenko. All rights reserved.http://www.hindawi.com/journals/ahep/2009/953987/We study the class of pulsating strings on AdS4×ℂℙ3. Using a generalized ansatz for pulsating string configurations we find new solutions of this class. Further we quasiclassically quantize the theory and obtain the first corrections to the energy. The latter, due to AdS/CFT correspondence, is supposed to give the anomalous dimensions of operators of the gauge theory dual 𝒩=6 Chern-Simons theory.H. Dimov and R. C. RashkovCopyright © 2009 H. Dimov and R. C. Rashkov. All rights reserved.http://www.hindawi.com/journals/ahep/2009/612063/Smooth double crossing of the phantom divide line wΛ=−1 has been found possible with a single minimally coupled scalar field for the most simple form of generalized k-essence cosmological model, in the presence of background cold dark matter. Such crossing is a sufficiently late time transient phenomenon and does not have any pathological behaviour.Abhik Kumar SanyalCopyright © 2009 Abhik Kumar Sanyal. All rights reserved.http://www.hindawi.com/journals/ahep/2009/278759/When analyzing the particle-like excitations in quantum field theory it is natural to regard the field mode corresponding to the particle momentum as an open quantum system, together with the opposite momentum mode. Provided that the state of the field is stationary, homogeneous, and isotropic, this scalar two-mode system can be equivalently represented in terms of a pair of quantum Brownian oscillators under a Gaussian approximation. In other words, the two-mode system behaves as if it were interacting linearly with some effective environment. In this paper we build the details of the effective linear coupling and the effective environment, and argue that this quantum Brownian representation provides a simple, universal, and nonperturbative characterization of any single particle-like excitation. As immediate applications of the equivalence, we reanalyze the interpretation of the self-energy in terms of decay rates in a general background state and present the master equation for the field mode corresponding to the particle momentum.Daniel ArteagaCopyright © 2009 Daniel Arteaga. All rights reserved.http://www.hindawi.com/journals/ahep/2009/234147/A semi-simple tensor extension of the Poincaré algebra is proposed for the arbitrary dimensions D. It is established that this extension is a direct sum of the D-dimensional Lorentz algebra so(D−1, 1) and D-dimensional anti-de Sitter (AdS) algebra so(D−1, 2). A supersymmetric also semi-simple generalization of this extension is constructed in the D=4 dimensions. It is shown that this generalization is a direct sum of the 4-dimensional Lorentz algebra so(3, 1) and orthosymplectic algebra osp(1, 4) (super-AdS algebra).Dmitrij V. Soroka and Vyacheslav A. SorokaCopyright © 2009 Dmitrij V. Soroka and Vyacheslav A. Soroka. All rights reserved.http://www.hindawi.com/journals/ahep/2009/640919/The conserving σ-ω-ρ mean-field approximation with nonlinear interactions of hadrons has been applied to examine properties of nuclear matter and hyperonic neutron stars. The nonlinear interactions that will produce density-dependent effective masses and coupling constants of hadrons are included in order to examine density correlations among properties of nuclear matter and neutron stars such as binding energy, incompressibility, K, symmetry energy, a4, hyperon-onset density, and maximum masses of neutron stars. The conditions of conserving approximations in order to maintain thermodynamic consistency to an approximation are essential for the analysis of density-dependent correlations.Schun T. Uechi and Hiroshi UechiCopyright © 2009 Schun T. Uechi and Hiroshi Uechi. All rights reserved.http://www.hindawi.com/journals/ahep/2009/905705/Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. Moreover, the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon of the Friedmann-Robertson-Walker universe as a thermodynamical system and investigate the thermodynamics of LQC in the semiclassical region. The effective density and effective pressure in the modified Friedmann equation from LQC not only determine the evolution of the universe in LQC scenario but also are actually found to be the thermodynamic quantities. This result comes from the energy definition in cosmology (the Misner-Sharp gravitational energy) and is consistent with thermodynamic laws. We prove that within the framework of loop quantum cosmology, the elementary equation of equilibrium thermodynamics is still valid.Li-Fang Li and Jian-Yang ZhuCopyright © 2009 Li-Fang Li and Jian-Yang Zhu. All rights reserved.http://www.hindawi.com/journals/ahep/2008/459290/We calculate modifications to the Schwarzschild solution by using a semiclassical analysis of loop quantum black hole. We obtain a metric inside the event horizon that coincides with the Schwarzschild solution near the horizon but that is substantially different at the Planck scale. In particular, we obtain a bounce of the S2 sphere for a minimum value of the radius and that it is possible to have another event horizon close to the r=0 point.Leonardo ModestoCopyright © 2008 Leonardo Modesto. All rights reserved.http://www.hindawi.com/journals/ahep/2008/982341/Using the method of QCD sum rules, we estimate the energy of the lowest hybrid charmonium state, and find it to be at the energy of the Ψ′(2S) state, about 600 MeV above the J/Ψ(1S) state. Since our solution is not consistent with a pure hybrid at this energy, we conclude that the Ψ′(2S) state is probably an admixed cc¯ and hybrid cc¯g state. From this conjecture, we find a possible explanation of the famous ρ−π puzzle.Leonard S. Kisslinger, Diana Parno, and Seamus RiordanCopyright © 2008 Leonard S. Kisslinger et al. All rights reserved.http://www.hindawi.com/journals/ahep/2008/521389/We review the status of the fourth-order (quartic in the spacetime curvature) terms induced by superstrings/M-theory (compactified on a warped torus) in the leading order with respect to the Regge slope parameter, and study their (nonperturbative) impact on the evolution of the Hubble scale in the context of the four-dimensional FRW cosmology. After taking into account the quantum ambiguities in the definition of the off-shell superstring effective action, we propose the generalized Friedmann equations, find the existence of their (de Sitter) exact inflationary solutions without a spacetime singularity, and constrain the ambiguities by demanding stability and the scale factor duality invariance of our solutions. The most naive (Bel-Robinson tensor squared) quartic terms are ruled out, thus giving the evidence for the necessity of extra quartic (Ricci tensor-dependent) terms in the off-shell gravitational effective action for superstrings. Our methods are generalizable to the higher orders in the spacetime curvature.Masao Iihoshi and Sergei V. KetovCopyright © 2008 Masao Iihoshi and Sergei V. Ketov. All rights reserved.http://www.hindawi.com/journals/ahep/2008/630414/The expansion rate of “intermediate inflation” lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of “intermediate inflation” reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.Abhik Kumar SanyalCopyright © 2008 Abhik Kumar Sanyal. All rights reserved.http://www.hindawi.com/journals/ahep/2008/682312/We show that it is possible to improve the infrared aspects of the standard treatment of the DGLAP-CS evolution theory to take into account a large class of higher-order corrections that significantly improve the precision of the theory for any given level of fixed-order calculation of its respective kernels. We illustrate the size of the effects we resum using the moments of the parton distributions.B. F. L. WardCopyright © 2008 B. F. L. Ward. All rights reserved.