http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/873051.htmlConfinement 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. Shevchenko© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/953987.htmlWe 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. Rashkov© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/612063.htmlSmooth 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 Sanyal© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/278759.htmlWhen 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 Arteaga© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/234147.htmlA 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. Soroka© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/640919.htmlThe 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 Uechi© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2009/905705.htmlLoop 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 Zhu© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/459290.htmlWe 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 Modesto© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/982341.htmlUsing 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 Riordan© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/521389.htmlWe 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. Ketov© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/630414.htmlThe 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 Sanyal© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/682312.htmlWe 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. Ward© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2008/739492.htmlThe SU(3)C⊗SU(3)L⊗U(1)X gauge model with minimal scalar sector, two Higgs triplets, is presented in detail. One of the vacuum expectation values u is a source of lepton-number violations and a reason for mixing among charged gauge bosons—the standard model W± and the bilepton gauge bosons Y±, as well as among the neutral non-Hermitian bilepton X0 and neutral gauge bosons—the Z and the new Z′. An exact diagonalization of the neutral gauge boson sector is derived, and bilepton mass splitting is also given. Because of these mixings, the lepton-number violating interactions exist in both charged and neutral gauge boson sectors. Constraints on vacuum expectation values of the model are estimated and u≃𝒪(1) GeV, v≃vweak=246 GeV, and ω≃𝒪(1) TeV. In this model, there are three physical scalars, two neutral and one charged, and eight Goldstone bosons—the needed number for massive gauge bosons. The minimal scalar sector can provide all fermions including quarks and neutrinos consistent masses in which some of them require one-loop radiative corrections.P. V. Dong and H. N. Long© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/082674.abs.htmlWe consider the possibility to gain information on the lepton mixing matrix element |Ue3| from an improved experimental limit on the effective neutrino mass governing neutrinoless double beta decay. We show that typically a lower limit on |Ue3| as a function of the smallest neutrino mass can be set. Furthermore, we give the values of the sum of neutrino masses and |Ue3| which are allowed and forbidden by an experimental upper limit on the effective mass. Alternative explanations for neutrinoless double beta decay, Dirac neutrinos or unexplained cosmological features would be required if future measurements showed that the values lie in the respective regions. Moreover, we show that a measurement of |Ue3| from neutrinoless double beta decay is very difficult due to the expected errors on the effective mass and the oscillation parameters.Alexander Merle and Werner Rodejohann© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/052750.abs.htmlThree (or four) straightforward experiments would contribute greatly to completing the spectroscopy of baryons and light mesons. In the baryon sector, data are needed on inelastic reactions from a polarised target with π± and K± beams up to ∼ 3 GeV/c. Similar data are needed in the light meson sector for p¯p interactions in the momentum range 0.3–2 GeV/c. In both cases, valuable information is to be obtained from longitudinal (L) and sideways (S) target polarisations as well as the conventional normal (N) polarisation. Thirdly, 3S1 and 3D1 mesons in the mass range 1–2.4 GeV could probably be separated either by diffractive dissociation of transversely polarised photons or by e+e− radiative return experiments using transversely and longitudinally polarised electrons.D. V. Bugg© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/021586.abs.htmlFollowing our recent work on the cosmological constant problem, in this letter we make a specific proposal regarding the fine structure (i.e., the spectrum) of dark energy. The proposal is motivated by a deep analogy between the blackbody radiation problem, which led to the development of quantum theory, and the cosmological constant problem, for which we have recently argued calls for a conceptual extension of the quantum theory. We argue that the fine structure of dark energy is governed by a Wien distribution, indicating its dual quantum and classical nature. We discuss observational consequences of such a picture of dark energy and constrain the distribution function.Vishnu Jejjala, Michael Kavic, and Djordje Minic© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/069835.abs.htmlIt is well known that one cannot construct a self-consistent quantum field theory describing the nonrelativistic electromagnetic interaction mediated by massive photons between a point-like electric charge and a magnetic monopole. We show that, indeed, this inconsistency arises in the classical theory itself. No semiclassic approximation or limiting procedure for ℏ→0 is used. As a result, the string attached to the monopole emerges as visible also if finite-range electromagnetic interactions are considered in classical framework.C. Cafaro, S. Capozziello, Ch. Corda, and S. A. Ali© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/039676.abs.htmlWe compute the effect of nondiagonal neutrino mass in li→ljγ in Supersymmetry (SUSY) theories with nontrivial quark-lepton complementarity and a flavor symmetry. The correlation matrix VM = UCKMUPMNS is such that its (1,3) entry, as preferred by the present experimental data, is zero. We do not assume that VM is bimaximal. Quark-lepton complementarity and the flavor symmetry strongly constrain the theory and we obtain a clear prediction for the contribution to μ→eγ and the τ decays τ→eγ and τ→μγ. If the Dirac neutrino Yukawa couplings are degenerate but the low-energy neutrino masses are not degenerate, then the lepton decays are related among them by the VM entries. On the other hand, if the Dirac neutrino Yukawa couplings are hierarchical or the low-energy neutrino masses are degenerate, then the prediction for the lepton decays comes from the UCKM hierarchy.Marco Picariello© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/090731.abs.htmlWe use the corrections to the Newton-Einstein secular precessions of the longitudes of the perihelia of the inner planets, phenomenologically estimated E.V. Pitjeva by fitting almost one century of data with the EPM2004 ephemerides, to constrain some long-range models of modified gravity recently put forth to address the dark energy and dark matter problems. They are the four-dimensional ones obtained with the addition of inverse powers and logarithm of some curvature invariants, and the DGP multidimensional braneworld model. After working out the analytical expressions of the secular perihelion precessions induced by the corrections to the Newtonian potential of such models, we compare them to the estimated extra-rates of perihelia by taking their ratio for different pairs of planets instead of using one perihelion at a time for each planet separately, as done so far in literature. The curvature invariants-based models are ruled out, even by rescaling by a factor 10 the errors in the estimated planetary orbital parameters. Less neat is the situation for the DGP model. Only the general relativistic Lense-Thirring effect, not included, as the other exotic models considered here, by Pitjeva in the EPM force models, passes such a test.Lorenzo Iorio© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/013458.abs.htmlWith a view towards applications for de Sitter, we construct the multiparametric q-deformation of the so(5,ℂ) algebra using the Faddeev-Reshetikhin-Takhtadzhyan (FRT) formalism.Chethan Krishnan and Edoardo Di Napoli© 2010, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/journals/ahep/2007/012387.abs.htmlToy models of a nonassociative quantum mechanics are presented. The Heisenberg equation of motion is modified using a nonassociative commutator. Possible physical applications of a nonassociative quantum mechanics are considered. The idea is discussed that a nonassociative algebra could be the operator language for the nonperturbative quantum theory. In such approach the nonperturbative quantum theory has observables and unobservables quantities.Vladimir Dzhunushaliev© 2010, Hindawi Publishing Corporation. All rights reserved.