201 research outputs found
Slash x Honduras Caribbean pine hybrids: an overview of nursery production systems Southeast Queensland, Australia
The Queensland Department of Primary Industries (DPI) Forestry has a requirement to produce 4.5 million trees per year for its plantation production program. This stock is raised at DPI Forestry nurseries in the southeast and far north of Queensland. To improve the productivity of its plantation estate, DPI Forestry has invested significant resources in the development of Pinus elliottii var. elliottii x. caribaea var. hondurensis (PEE x PCH) F. and FZ hybrid families and clones as well as associated delivery systems, including extensive clonal testing and hedge multiplication programs. More recently, it has commenced small-scale trials to produce "micro-cuttings." Past and present production techniques, including open-root, containerized seedling and cutting systems, and approaches to hedge management are presented in this paper
Spontaneous magnetization of the XXZ Heisenberg spin-1/2 chain
Determinant representations of form factors are used to represent the
spontaneous magnetization of the Heisenberg XXZ chain (Delta >1) on the finite
lattice as the ratio of two determinants. In the thermodynamic limit (the
lattice of infinite length), the Baxter formula is reproduced in the framework
of Algebraic Bethe Ansatz. It is shown that the finite size corrections to the
Baxter formula are exponentially small.Comment: 18 pages, Latex2
Scalar products in generalized models with SU(3)-symmetry
We consider a generalized model with SU(3)-invariant R-matrix, and review the
nested Bethe Ansatz for constructing eigenvectors of the transfer matrix. A sum
formula for the scalar product between generic Bethe vectors, originally
obtained by Reshetikhin [11], is discussed. This formula depends on a certain
partition function Z(\{\lambda\},\{\mu\}|\{w\},\{v\}), which we evaluate
explicitly. In the limit when the variables \{\mu\} or \{v\} approach infinity,
this object reduces to the domain wall partition function of the six-vertex
model Z(\{\lambda\}|\{w\}). Using this fact, we obtain a new expression for the
off-shell scalar product (between a generic Bethe vector and a Bethe
eigenvector), in the case when one set of Bethe variables tends to infinity.
The expression obtained is a product of determinants, one of which is the
Slavnov determinant from SU(2) theory. It extends a result of Caetano [13].Comment: 28 pages, 12 figures, greatly lengthened exposition in v3; 2
appendices and extra references adde
Order Parameters of the Dilute A Models
The free energy and local height probabilities of the dilute A models with
broken \Integer_2 symmetry are calculated analytically using inversion and
corner transfer matrix methods. These models possess four critical branches.
The first two branches provide new realisations of the unitary minimal series
and the other two branches give a direct product of this series with an Ising
model. We identify the integrable perturbations which move the dilute A models
away from the critical limit. Generalised order parameters are defined and
their critical exponents extracted. The associated conformal weights are found
to occur on the diagonal of the relevant Kac table. In an appropriate regime
the dilute A model lies in the universality class of the Ising model in a
magnetic field. In this case we obtain the magnetic exponent
directly, without the use of scaling relations.Comment: 53 pages, LaTex, ITFA 93-1
Critical behavior of hard-core lattice gases: Wang-Landau sampling with adaptive windows
Critical properties of lattice gases with nearest-neighbor exclusion are
investigated via the adaptive-window Wang-Landau algorithm on the square and
simple cubic lattices, for which the model is known to exhibit an Ising-like
phase transition. We study the particle density, order parameter,
compressibility, Binder cumulant and susceptibility. Our results show that it
is possible to estimate critical exponents using Wang-Landau sampling with
adaptive windows. Finite-size-scaling analysis leads to results in fair
agreement with exact values (in two dimensions) and numerical estimates (in
three dimensions).Comment: 20 pages, 11 figure
R-matrices of U_qOSP(1,2) for highest weight representations of U_qOSP(1,2) for general q and q is an odd root of unity
We obtain the formula for intertwining operator(R-matrix) of quantum
universal enveloping superalgebra U_qOSP(1,2) for U_qOSP(1,2)-Verma modules. By
its restriction we obtain the R-matrix for two semiperiodic(semicyclic), two
spin-j and spin-j and semiperiodic representationsComment: 9 pages, Yerevan preprint 1993, LATE
New Fundamental Symmetries of Integrable Systems and Partial Bethe Ansatz
We introduce a new concept of quasi-Yang-Baxter algebras. The quantum
quasi-Yang-Baxter algebras being simple but non-trivial deformations of
ordinary algebras of monodromy matrices realize a new type of quantum dynamical
symmetries and find an unexpected and remarkable applications in quantum
inverse scattering method (QISM). We show that applying to quasi-Yang-Baxter
algebras the standard procedure of QISM one obtains new wide classes of quantum
models which, being integrable (i.e. having enough number of commuting
integrals of motion) are only quasi-exactly solvable (i.e. admit an algebraic
Bethe ansatz solution for arbitrarily large but limited parts of the spectrum).
These quasi-exactly solvable models naturally arise as deformations of known
exactly solvable ones. A general theory of such deformations is proposed. The
correspondence ``Yangian --- quasi-Yangian'' and `` spin models ---
quasi- spin models'' is discussed in detail. We also construct the
classical conterparts of quasi-Yang-Baxter algebras and show that they
naturally lead to new classes of classical integrable models. We conjecture
that these models are quasi-exactly solvable in the sense of classical inverse
scattering method, i.e. admit only partial construction of action-angle
variables.Comment: 49 pages, LaTe
Exact solution of the six-vertex model with domain wall boundary condition. Critical line between ferroelectric and disordered phases
This is a continuation of the papers [4] of Bleher and Fokin and [5] of
Bleher and Liechty, in which the large asymptotics is obtained for the
partition function of the six-vertex model with domain wall boundary
conditions in the disordered and ferroelectric phases, respectively. In the
present paper we obtain the large asymptotics of on the critical line
between these two phases.Comment: 22 pages, 6 figures, to appear in the Journal of Statistical Physic
New Formula for the Eigenvectors of the Gaudin Model in the sl(3) Case
We propose new formulas for eigenvectors of the Gaudin model in the \sl(3)
case. The central point of the construction is the explicit form of some
operator P, which is used for derivation of eigenvalues given by the formula , where , fulfil
the standard well-know Bethe Ansatz equations
Thermodynamic Bethe Ansatz for the Spin-1/2 Staggered XXZ- Model
We develop the technique of Thermodynamic Bethe Ansatz to investigate the
ground state and the spectrum in the thermodynamic limit of the staggered
models proposed recently as an example of integrable ladder model. This model
appeared due to staggered inhomogeneity of the anisotropy parameter
and the staggered shift of the spectral parameter. We give the structure of
ground states and lowest lying excitations in two different phases which occur
at zero temperature.Comment: 21 pages, 1 figur
- …