3,912 research outputs found

    Infrared Behaviour of Massless Integrable Flows entering the Minimal Models from phi_31

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    It is known that any minimal model M_p receives along its phi_31 irrelevant direction *two* massless integrable flows: one from M_{p+1} perturbed by phi_{13}, the other from Z_{p-1} parafermionic model perturbed by its generating parafermion field. By comparing Thermodynamic Bethe Ansatz data and ``predictions'' of infrared Conformal Perturbation Theory we show that these two flows are received by M_p with opposite coupling constants of the phi_31 irrelevant perturbation. Some comments on the massless S matrices of these two flows are added.Comment: 12 pages, Latex - One misprinted (uninfluent) coefficient corrected in Tab.

    Nonperturbative study of the two-frequency sine-Gordon model

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    The two-frequency sine-Gordon model is examined. The focus is mainly on the case when the ratio of the frequencies is 1/2, given the recent interest in the literature. We discuss the model both in a perturbative (form factor perturbation theory) and a nonperturbative (truncated conformal space approach) framework, and give particular attention to a phase transition conjectured earlier by Delfino and Mussardo. We give substantial evidence that the transition is of second order and that it is in the Ising universality class. Furthermore, we check the UV-IR operator correspondence and conjecture the phase diagram of the theory.Comment: Minor corrections, LaTeX2e, 39 pages, 26 figures (4 pslatex, 1 postscript and 21 eps

    Scaling Functions in the Odd Charge Sector of Sine-Gordon/Massive Thirring Theory

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    A non-linear integral equation (NLIE) governing the finite size effects of excited states of even topological charge in the sine-Gordon (sG) / massive Thirring (mTh) field theory, deducible from a light-cone lattice formulation of the model, has been known for some time. In this letter we conjecture an extension of this NLIE to states with odd topological charge, thus completing the spectrum of the theory. The scaling functions obtained as solutions to our conjectured NLIE are compared successfully with Truncated Conformal Space data and the construction is shown to be compatible with all other facts known about the local Hilbert spaces of sG and mTh models. With the present results we have achieved a full control over the finite size behaviour of energy levels of sG/mTh theory.Comment: LaTeX2e, 12 pp., 3 eps figs. Remarks on locality adde

    Truncated Conformal Space at c=1, Nonlinear Integral Equation and Quantization Rules for Multi-Soliton States

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    We develop Truncated Conformal Space (TCS) technique for perturbations of c=1 Conformal Field Theories. We use it to give the first numerical evidence of the validity of the non-linear integral equation (NLIE) derived from light-cone lattice regularization at intermediate scales. A controversy on the quantization of Bethe states is solved by this numerical comparison and by using the locality principle at the ultra- violet fixed point. It turns out that the correct quantization for pure hole states is the one with half-integer quantum numbers originally proposed by Mariottini et al. Once the correct rule is imposed, the agreement between TCS and NLIE for pure hole states turns out to be impressive.Comment: 12 pages, 5 eps figures, LaTeX2e. Reference added, changes in the discussion of TCS metho

    Interacting Bose and Fermi gases in low dimensions and the Riemann hypothesis

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    We apply the S-matrix based finite temperature formalism to non-relativistic Bose and Fermi gases in 1+1 and 2+1 dimensions. In the 2+1 dimensional case, the free energy is given in terms of Roger's dilogarithm in a way analagous to the relativistic 1+1 dimensional case. The 1d fermionic case with a quasi-periodic 2-body potential provides a physical framework for understanding the Riemann hypothesis.Comment: version 3: additional appendix explains how the ν\nu to 1ν1-\nu duality of Riemann's ζ(ν)\zeta (\nu) follows from a special modular transformation in a massless relativistic theor

    The Effect of Residual Roundup on Showy Milkweed Growth and Cardenolide Production

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    Western monarch butterfly populations have sharply declined over the last three decades largely due to destruction of their habitat and larval food source, milkweed (Asclepias spp.). In order to aid reestablishment of milkweed habitat in support of Western monarch populations, the effects of soil pollutants and additives on the plant’s growth and toxin production should be examined. We evaluated five growth parameters and cardenolide concentration of showy milkweed (A. speciosa) exposed to various soil treatments of Roundup and arbuscular mycorrhizal fungi in controlled greenhouse conditions. Our results suggest that residual Roundup in soil does not affect cardenolide concentrations in showy milkweed but may interact with arbuscular mycorrhizal fungus symbionts to affect growth. More research is needed in order to understand the relationship between Roundup and mycorrhizal symbionts, but our results suggest that Roundup pollutants remaining in soil will not adversely affect milkweed restoration efforts in support of the imperiled Western monarch butterfly

    Numerical study of O(a) improved Wilson quark action on anisotropic lattice

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    The O(a)O(a) improved Wilson quark action on the anisotropic lattice is investigated. We carry out numerical simulations in the quenched approximation at three values of lattice spacing (aσ1=1a_{\sigma}^{-1}=1--2 GeV) with the anisotropy ξ=aσ/aτ=4\xi=a_{\sigma}/a_{\tau}=4, where aσa_{\sigma} and aτa_{\tau} are the spatial and the temporal lattice spacings, respectively. The bare anisotropy γF\gamma_F in the quark field action is numerically tuned by the dispersion relation of mesons so that the renormalized fermionic anisotropy coincides with that of gauge field. This calibration of bare anisotropy is performed to the level of 1 % statistical accuracy in the quark mass region below the charm quark mass. The systematic uncertainty in the calibration is estimated by comparing the results from different types of dispersion relations, which results in 3 % on our coarsest lattice and tends to vanish in the continuum limit. In the chiral limit, there is an additional systematic uncertainty of 1 % from the chiral extrapolation. Taking the central value γF=γF\gamma_F=\gamma_F^* from the result of the calibration, we compute the light hadron spectrum. Our hadron spectrum is consistent with the result by UKQCD Collaboration on the isotropic lattice. We also study the response of the hadron spectrum to the change of anisotropic parameter, γFγF+δγF\gamma_F \to \gamma_F^* + \delta\gamma_F. We find that the change of γF\gamma_F by 2 % induces a change of 1 % in the spectrum for physical quark masses. Thus the systematic uncertainty on the anisotropic lattice, as well as the statistical one, is under control.Comment: 27 pages, 25 eps figures, LaTe
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