3,912 research outputs found
Infrared Behaviour of Massless Integrable Flows entering the Minimal Models from phi_31
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
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
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
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
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 to
duality of Riemann's follows from a special modular
transformation in a massless relativistic theor
The Effect of Residual Roundup on Showy Milkweed Growth and Cardenolide Production
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
The 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 (--2 GeV) with the
anisotropy , where and are
the spatial and the temporal lattice spacings, respectively. The bare
anisotropy 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 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, . We find that the change
of 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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