Scalar Condensate Research Articles

Holographic aspects of two-charged dilatonic black hole in AdS5

We study certain features of a strongly coupled theory whose gravitational dual is given by two-charge dilatonic black hole in AdS5 which has recently been used to study holographic Fermi liquids. By making use of the gravity description, we have studied conductivity, holographic entanglement entropy and dynamics of a charged scalar field. In particular at low energy we find that the temperature dependence of the real part of the conductivity goes as T 3 and the background is stable against scalar condensations.

Processing of Surfactant Templated Nano-Structured Silica Films Using Compressed Carbon Dioxide as Interpreted from In Situ Fluorescence Spectroscopy

The local environment and dynamics of compressed carbon dioxide (CO(2)) penetration in surfactant templated silica film synthesis is interpreted from the in situ fluorescence emission spectra of pyrene (Py) and a modified pyrene probe. Pyrene emission in cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) templated silica films is monitored immediately after casting and during processing with gaseous and supercritical (sc) CO(2) (17-172 bar, 45 °C). The solvatochromic emission spectra of pyrene in CTAB templated films suggest CO(2) penetration in both the micelle interface and its interior. An anchored derivative of pyrene, 1-pyrenehexadecanoic acid (C(16)-pyr), is established for probing CPB films, where the pyrene moiety is preferentially oriented toward the micelle interior, thus limiting quenching by the pyridinium headgroup of CPB. CO(2) processing of CPB templated silica films results in an increase in the time scale for probe mobility, suggesting an increased time scale of silica condensation through CO(2) processing. The mobility of C(16)-pyr increases with pressure from gaseous to sc CO(2) processing and persists for over 5 h for sc CO(2) processing at 172 bar and 45 °C compared to about 25 min for the unprocessed film. The delivery of CO(2) soluble solutes to specific regions of surfactant templated mesoporous materials is examined via the nonradiative energy transfer (NRET) between pyrene and CO(2)-solubilized naphthalene.

Excitation transport through a domain wall in a Bose-Einstein condensate

We investigate the tunneling properties of collective excitations through a domain wall in the ferromagnetic phase of a spin-1 spinor Bose-Einstein condensate. Within the mean-field theory at $T=0$, we show that the transverse spin wave undergoes perfect reflection in the low-energy limit. This reflection property differs considerably from that of a domain wall in a Heisenberg ferromagnet where spin-wave excitations exhibit perfect transmission at arbitrary energy. When the Bogoliubov mode is scattered from this domain wall soliton, the transmission and reflection coefficients exhibit pronounced nonmonotonicity. In particular, we find perfect reflection of the Bogoliubov mode at energies where bound states appear. This is in stark contrast to the perfect transmission of the Bogoliubov mode with arbitrary energy through a dark soliton in a scalar Bose-Einstein condensate.

Imprints of cosmic phase transition in inflationary gravitational waves

We discuss the effects of cosmic phase transition on the spectrum of primordial gravitational waves generated during inflation. The energy density of the scalar condensation responsible for the phase transition may become sizable at the epoch of phase transition, which significantly affects the evolution of the universe. As a result, the amplitudes of the gravitational waves at high frequency modes are suppressed. Thus the gravitational wave spectrum can be a probe of phase transition in the early universe.

Charmonium mass in hot and dense hadronic matter

We investigate mass shifts of charmonia driven by change of the gluon condensate below but near transition temperatures at finite baryonic chemical potential. Extending previous prescription on the relation between gluon condensates and thermodynamic quantities, we model the gluon condensates of hadronic matter at finite temperature and baryonic chemical potential such that the scalar gluon condensate fits with the latest lattice QCD data. By making use of the QCD sum rule and the second order Stark effect, we find that the smoother transition in the full QCD can lead to moderate mass shifts of charmonia even below the transition temperature. We also find larger mass shift at fixed temperature as chemical potential increases. Existing data on charmonium-charmonium ratio is found to be consistent with the statistical hadronization scenario including the obtained mass shift.

Zero temperature lattice Weinberg-Salam model for the values of the cutoffΛ∼1 TeV

The lattice Weinberg - Salam model at zero temperature is investigated numerically. We consider the model for the following values of the coupling constants: the Weinberg angle $\theta_W \sim 30^o$, the fine structure constant $\alpha \sim 1/150$, the Higgs mass $M_H \sim 150$ GeV. We find that the fluctuational region begins at the values of the cutoff $\Lambda$ above about 0.8 TeV. In this region the average distance between Nambu monopoles is close to their sizes. At $\Lambda > 1$ TeV the Nambu monopole currents percolate. Within the fluctuational region the considered definitions of the scalar field condensate give values that differ from the expected one $2 M_Z/g_z$. We consider the given results as an indication that the nonperturbative effects may be present in the Weinberg - Salam model at the large values of the cutoff. Our numerical results were obtained on the lattices of sizes up to $16^3\times 32$.

Two-dimensional moist stratified turbulence and the emergence of vertically sheared horizontal flows

Moist stratified turbulence is studied in a two-dimensional Boussinesq system influenced by condensation and evaporation. The problem is set in a periodic domain and employs simple evaporation and condensation schemes, wherein both the processes push parcels towards saturation. Numerical simulations demonstrate the emergence of a moist turbulent state consisting of ordered structures with a clear power-law type spectral scaling from initially spatially uncorrelated conditions. An asymptotic analysis in the limit of rapid condensation and strong stratification shows that, for initial conditions with enough water substance to saturate the domain, the equations support a straightforward state of moist balance characterized by a hydrostatic, saturated, vertically sheared horizontal flow (VSHF). For such initial conditions, by means of long time numerical simulations, the emergence of moist balance is verified. Specifically, starting from uncorrelated data, subsequent to the development of a moist turbulent state, the system experiences a rather abrupt transition to a regime which is close to saturation and dominated by a strong VSHF. On the other hand, initial conditions which do not have enough water substance to saturate the domain, do not attain moist balance. Rather, the system is observed to remain in a turbulent state and oscillates about moist balance. Even though balance is not achieved with these general initial conditions, the time scale of oscillation about moist balance is much larger than the imposed time scale of condensation and evaporation, thus indicating a distinct dominant slow component in the moist stratified two-dimensional turbulent system.

A new approach to physics of nuclei

We employ the QCD sum rules method for description of nucleons in nuclear matter. We show that this approach provides a consistent formalism for solving various problems of nuclear physics. Such nucleon characteristics as the Dirac effective mass m* and the vector self-energy Σ V are expressed in terms of the in-medium values of QCD condensates. The values of these parameters at saturation density and the dependence on the baryon density and on the neutron-to-proton density ratio is in agreement with the results, obtained by conventional nuclear physics methods. The contributions to m* and Σ V are related to observables and do not require phenomenological parameters. The scalar interaction is shown to be determined by the pion-nucleon σ term. The nonlinear behavior of the scalar condensate may appear to provide a possible mechanism of the saturation. The approach provided reasonable results for renormalization of the axial coupling constant, for the contribution of the strong interactions to the neutron-proton mass difference and for the behavior of the structure functions of the in-medium nucleon. The approach enables to solve the problems which are difficult or unaccessible for conventional nuclear physics methods. The method provides guidelines for building the nuclear forces. The three-body interactions emerge within the method in a natural way. Their rigorous calculation will be possible in the framework of self-consistent calculation in nuclear matter of the scalar condensate and of the nucleon effective mass m*.

NOTE ON ANALYTICAL STUDIES OF ONE-DIMENSIONAL HOLOGRAPHIC SUPERCONDUCTORS

We employ the variational method for the Sturm–Liouville eigenvalue problem to analytically study phase transition of one-dimensional holographic superconductors. It is shown that this method is not a very powerful method to analytically calculate the properties of holographic superconductors. From the analytical treatment of scalar operator condensate at critical temperature, we also show that the mean-field critical exponent 1/2 results from the coupling term between scalar field and vector field, which may be an universal property of holographic superconductors with a similar coupling term in their equations of motion.

Massive cosmologies

We explore the cosmological solutions of a recently proposed extension of general relativity with a Lorentz-invariant mass term. We show that the same constraint that removes the Boulware-Deser ghost in this theory also prohibits the existence of homogeneous and isotropic cosmological solutions. Nevertheless, within domains of the size of inverse graviton mass we find approximately homogeneous and isotropic solutions that can well describe the past and present of the Universe. At energy densities above a certain crossover value, these solutions approximate the standard Friedmann-Robertson-Walker evolution with great accuracy. As the Universe evolves and density drops below the crossover value the inhomogeneities become more and more pronounced. In the low-density regime each domain of the size of the inverse graviton mass has essentially non-Friedmann-Robertson-Walker. cosmology. This scenario imposes an upper bound on the graviton mass, which we roughly estimate to be an order of magnitude below the present-day value of the Hubble parameter. The bound becomes especially restrictive if one utilizes an exact self-accelerated solution that this theory offers. Although the above are robust predictions of massive gravity with an explicit mass term, we point out that if the mass parameter emerges from some additional scalar field condensation, the constraint no longer forbids the homogeneous and isotropic cosmologies. In the latter case, there will exist an extra light scalar field at cosmological scales, which is screened by the Vainshtein mechanism at shorter distances.

Matone's Relation of Super Yang—Mills and Spectrum of Toda Chain

In super Yang-Mills theory, the Matone's relation relates instanton corrections of the prepotential to instanton corrections of scalar field condensation 〈Trϕ2〉. This relation has been proved to hold for Omega deformed theories too, using localization method. In this paper, we first give a case study supporting the relation, which does not rely on the localization technique. Especially, we show that the magnetic expansion also satisfies a relation of Matone's type. Then we discuss implication of the relation for the spectrum of periodic Toda chain, in the context of recently proposed Nekrasov-Shatashvili scheme.

Stability of Gauss-Bonnet black holes in anti-de Sitter space-time against scalar field condensation

We study the stability of static, hyperbolic Gauss-Bonnet black holes in ($4+1$)-dimensional anti-de Sitter (AdS) space-time against the formation of scalar hair. Close to extremality the black holes possess a near-horizon topology of ${\mathrm{AdS}}_{2}\ifmmode\times\else\texttimes\fi{}{H}^{3}$ such that within a certain range of the scalar field mass one would expect that they become unstable to the condensation of an uncharged scalar field. We confirm this numerically and observe that there exists a family of hairy black hole solutions labeled by the number of nodes of the scalar field function. We construct explicit examples of solutions with a scalar field that possesses zero nodes, one node, and two nodes, respectively, and show that the solutions with nodes persist in the limit of Einstein gravity, i.e. for vanishing Gauss-Bonnet coupling. We observe that the interval of the mass for which scalar field condensation appears decreases with increasing Gauss-Bonnet coupling and/or with increasing node number.

Enhancement of spin coherence in a spin-1 Bose-Einstein condensate by dynamical decoupling approaches

We study the enhancement of spin coherence with periodic, concatenated, or Uhrig dynamical decoupling $N$-pulse sequences in a spin-1 Bose-Einstein condensate, where the intrinsic dynamical instability in such a ferromagnetically interacting condensate causes spin decoherence and eventually leads to a multiple spatial-domain structure or a spin texture. Our results show that all three sequences successfully enhance the spin coherence by pushing the wave vector of the most unstable mode in the condensate to a larger value. Among the three sequences with the same number of pulses, the concatenated one shows the best performance in preserving the spin coherence. More interestingly, we find that all three sequences exactly follow the same enhancement law, ${k}_{\ensuremath{-}}{T}^{1/2}=c$, with ${k}_{\ensuremath{-}}$ the wave vector of the most unstable mode, $T$ the sequence period, and $c$ a sequence-dependent constant. Such a law between ${k}_{\ensuremath{-}}$ and $T$ is also derived analytically for an attractive scalar Bose-Einstein condensate subjected to a periodic dynamical decoupling sequence.

NEW BOUND STATES OF HEAVY QUARKS AT LHC AND TEVATRON

The present paper is based on the assumption that heavy quarks bound states exist in the Standard Model (SM). Considering New Bound States (NBS) of top–antitop quarks (named T-balls) we have shown that: (1) there exists the scalar 1S-bound state of [Formula: see text]; (2) the forces which bind the top-quarks are very strong and almost completely compensate the mass of the twelve top–antitop-quarks in the scalar NBS; (3) such strong forces are produced by the Higgs–top-quarks interaction with a large value of the top-quark Yukawa coupling constant gt≃1. Theory also predicts the existence of the NBS [Formula: see text], which is a color triplet and a fermion similar to the t'-quark of the fourth generation. We have also considered the "b-quark-replaced" NBS, estimated the masses of the lightest fermionic NBS: M NBS ≳300 GeV , and discussed the larger masses of T-balls. We have developed a theory of the scalar T-ball's condensate and predicted the existence of three SM phases. Searching for heavy quark bound states at the Tevatron and LHC is discussed. We have constructed the possible form-factors of T-balls, and estimated the charge multiplicity coming from the T-ball's decays.

Vortex flow for a holographic superconductor

We investigate energy dissipation associated with the motion of the scalar condensate in a holographic superconductor model constructed from the charged scalar field coupled to the Maxwell field. Upon application of constant magnetic and electric fields, we analytically construct the vortex flow solution, and find the vortex flow resistance near the second-order phase transition where the scalar condensate begins. The characteristic feature of the non-equilibrium state agrees with the one predicted by the time-dependent Ginzburg-Landau(TDGL) theory. We evaluate the kinetic coefficient in the TDGL equation along the line of the second-order phase transition. At zero magnetic field, the other coefficients in the TDGL equation are also evaluated just below the critical temperature.

Comments on non-Fermi liquids in the presence of a condensate

We study the effects of a scalar condensate on a class of 2+1 dimensional non-Fermi liquids by introducing fermionic probes in the corresponding asymptotically AdS4 black hole backgrounds. For the range of parameters and the type of couplings we consider, the system does not develop a gap and resembles a conventional (Landau) Fermi liquid. The detailed properties of the system depend strongly on the parameters, in a model-dependent way.

Density waves in quark matter within the Nambu-Jona-Lasinio model in an external magnetic field

The possibility of forming static dual scalar and pseudo-scalar density wave condensates in dense quark matter is considered for the Nambu-Jona-Lasinio model in an external magnetic field. Within a mean-field approximation, the effective potential of the theory is obtained and its extrema are numerically studied and a phase diagram of the system is constructed. It is shown that the presence of a magnetic field favors the formation of spatially inhomogeneous condensate configurations at low temperatures.

A scalar field condensation instability of rotating Anti-de Sitter black holes

Near-extreme Reissner-Nordstrom-anti-de Sitter black holes are unstable against the condensation of an uncharged scalar field with mass close to the Breitenlohner-Freedman bound. It is shown that a similar instability afflicts near-extreme large rotating AdS black holes, and near-extreme hyperbolic Schwarzschild-AdS black holes. The resulting nonlinear hairy black hole solutions are determined numerically. Some stability results for (possibly charged) scalar fields in black hole backgrounds are proved. For most of the extreme black holes we consider, these demonstrate stability if the ``effective mass" respects the near-horizon BF bound. Small spherical Reissner-Nordstrom-AdS black holes are an interesting exception to this result.

Chiral density waves in quark matter within the Nambu–Jona-Lasinio model in an external magnetic field

A possibility of formation of static dual scalar and pseudoscalar density wave condensates in dense quark matter is considered for the Nambu--Jona-Lasinio model in an external magnetic field. Within a mean-field approximation, the effective potential of the theory is obtained and its minima are numerically studied; a phase diagram of the system is constructed. It is shown that the presence of a magnetic field favors the formation of spatially inhomogeneous condensate configurations at low temperatures and arbitrary non-zero values of the chemical potential.

Hybrid Neutron Stars Based on a Modified PNJL Model

We discuss a three-flavor Nambu--Jona-Lasinio (NJL) type quantum field theoretical approach to the quark matter equation of state (EoS) with scalar diquark condensate, isoscalar vector mean field and Kobayashi-Maskawa-'t Hooft (KMT) determinant interaction. While often the diquark and vector meson couplings are considered as free parameters, we will fix them here to their values according to the Fierz transformation of a one-gluon exchange interaction. In order to estimate the effect of a possible change in the vacuum pressure of the gluon sector at finite baryon density we exploit a recent modification of the Polyakov-loop NJL (mPNJL) model which introduces a parametric density dependence of the Polyakov-loop potential also at T=0, thus being relevant for compact star physics. We use a Dirac-Brueckner-Hartree-Fock (DBHF) EoS for the hadronic matter phase and discuss results for mass-radius relationships following from a solution of the TOV equations for such a hybrid EoS in the context of observational constraints from selected objects.