6,297 research outputs found
Universal Bethe ansatz solution for the Temperley-Lieb spin chain
We consider the Temperley-Lieb (TL) open quantum spin chain with "free"
boundary conditions associated with the spin- representation of
quantum-deformed . We construct the transfer matrix, and determine its
eigenvalues and the corresponding Bethe equations using analytical Bethe
ansatz. We show that the transfer matrix has quantum group symmetry, and we
propose explicit formulas for the number of solutions of the Bethe equations
and the degeneracies of the transfer-matrix eigenvalues. We propose an
algebraic Bethe ansatz construction of the off-shell Bethe states, and we
conjecture that the on-shell Bethe states are highest-weight states of the
quantum group. We also propose a determinant formula for the scalar product
between an off-shell Bethe state and its on-shell dual, as well as for the
square of the norm. We find that all of these results, except for the
degeneracies and a constant factor in the scalar product, are universal in the
sense that they do not depend on the value of the spin. In an appendix, we
briefly consider the closed TL spin chain with periodic boundary conditions,
and show how a previously-proposed solution can be improved so as to obtain the
complete (albeit non-universal) spectrum.Comment: v2: 21 pages; minor revisions, references added, publishe
Algebraic Bethe ansatz for the Temperley-Lieb spin-1 chain
We use the algebraic Bethe ansatz to obtain the eigenvalues and eigenvectors
of the spin-1 Temperley-Lieb open quantum chain with "free" boundary
conditions. We exploit the associated reflection algebra in order to prove the
off-shell equation satisfied by the Bethe vectors.Comment: v2: 28 pages; minor revisions, publishe
Multivariate Survival Mixed Models for Genetic Analysis of Longevity Traits
A class of multivariate mixed survival models for continuous and discrete
time with a complex covariance structure is introduced in a context of
quantitative genetic applications. The methods introduced can be used in many
applications in quantitative genetics although the discussion presented
concentrates on longevity studies. The framework presented allows to combine
models based on continuous time with models based on discrete time in a joint
analysis. The continuous time models are approximations of the frailty model in
which the hazard function will be assumed to be piece-wise constant. The
discrete time models used are multivariate variants of the discrete relative
risk models. These models allow for regular parametric likelihood-based
inference by exploring a coincidence of their likelihood functions and the
likelihood functions of suitably defined multivariate generalized linear mixed
models. The models include a dispersion parameter, which is essential for
obtaining a decomposition of the variance of the trait of interest as a sum of
parcels representing the additive genetic effects, environmental effects and
unspecified sources of variability; as required in quantitative genetic
applications. The methods presented are implemented in such a way that large
and complex quantitative genetic data can be analyzed.Comment: 36 pages, 2 figures, 3 table
“LAS ADQUISICIONES VÍA LICITACIÓN PÚBLICA, UNA PERSPECTIVA DESDE LA ADMINISTRACIÓN PÚBLICA; ESTUDIO DE CASO MUNICIPIO DE TENANCINGO, ESTADO DE MÉXICO”
Con ello, el principal objetivo de la presente investigación será, conocer y describir cómo realiza las adquisiciones de recursos materiales el gobierno Municipal de Tenancingo, por medio del proceso de licitación pública a fin de verificar las desviaciones que marca la misma administración pública del marco lega
The integrable quantum group invariant A_{2n-1}^(2) and D_{n+1}^(2) open spin chains
A family of A_{2n}^(2) integrable open spin chains with U_q(C_n) symmetry was
recently identified in arXiv:1702.01482. We identify here in a similar way a
family of A_{2n-1}^(2) integrable open spin chains with U_q(D_n) symmetry, and
two families of D_{n+1}^(2) integrable open spin chains with U_q(B_n) symmetry.
We discuss the consequences of these symmetries for the degeneracies and
multiplicities of the spectrum. We propose Bethe ansatz solutions for two of
these models, whose completeness we check numerically for small values of n and
chain length N. We find formulas for the Dynkin labels in terms of the numbers
of Bethe roots of each type, which are useful for determining the corresponding
degeneracies. In an appendix, we briefly consider D_{n+1}^(2) chains with other
integrable boundary conditions, which do not have quantum group symmetry.Comment: 47 pages; v2: two references added and minor change
A tale of two Bethe ans\"atze
We revisit the construction of the eigenvectors of the single and double-row
transfer matrices associated with the Zamolodchikov-Fateev model, within the
algebraic Bethe ansatz method. The left and right eigenvectors are constructed
using two different methods: the fusion technique and Tarasov's construction. A
simple explicit relation between the eigenvectors from the two Bethe ans\"atze
is obtained. As a consequence, we obtain the Slavnov formula for the scalar
product between on-shell and off-shell Tarasov-Bethe vectors.Comment: 28 pages; v2: 30 pages, added proof of (4.40) and (5.39), minor
changes to match the published versio
Monitoring water-soil dynamics and tree survival using soil sensors under a big data approach
ArticleThe high importance of green urban planning to ensure access to green areas requires
modern and multi-source decision-support tools. The integration of remote sensing data and sensor
developments can contribute to the improvement of decision-making in urban forestry. This study
proposes a novel big data-based methodology that combines real-time information from soil sensors
and climate data to monitor the establishment of a new urban forest in semi-arid conditions. Water-soil
dynamics and their implication in tree survival were analyzed considering the application of di erent
treatment restoration techniques oriented to facilitate the recovery of tree and shrub vegetation in
the degraded area. The synchronized data-capturing scheme made it possible to evaluate hourly,
daily, and seasonal changes in soil-water dynamics. The spatial variation of soil-water dynamics
was captured by the sensors and it highly contributed to the explanation of the observed ground
measurements on tree survival. The methodology showed how the e ciency of treatments varied
depending on species selection and across the experimental design. The use of retainers for improving
soil moisture content and adjusting tree-watering needs was, on average, the most successful
restoration technique. The results and the applied calibration of the sensor technology highlighted the
random behavior of water-soil dynamics despite the small-scale scope of the experiment. The results
showed the potential of this methodology to assess watering needs and adjust watering resources to
the vegetation status using real-time atmospheric and soil datainfo:eu-repo/semantics/publishedVersio
Nonlocality in sequential correlation scenarios
As first shown by Popescu [S. Popescu, Phys. Rev. Lett. 74, 2619 (1995)],
some quantum states only reveal their nonlocality when subjected to a sequence
of measurements while giving rise to local correlations in standard Bell tests.
Motivated by this manifestation of "hidden nonlocality" we set out to develop a
general framework for the study of nonlocality when sequences of measurements
are performed. Similar to [R. Gallego et al., Phys. Rev. Lett. 109, 070401
(2013)] our approach is operational, i.e. the task is to identify the set of
allowed operations in sequential correlation scenarios and define nonlocality
as the resource that cannot be created by these operations. This leads to a
characterisation of sequential nonlocality that contains as particular cases
standard nonlocality and hidden nonlocality.Comment: 13 pages, 3 figure
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