419 research outputs found
Boundary Bound States in Affine Toda Field Theory
We demonstrate that the generalization of the Coleman-Thun mechanism may be
applied to the situation, when considering scattering processes in
1+1-dimensions in the presence of reflecting boundaries. For affine Toda field
theories we find that the binding energies of the bound states are always half
the sum over a set of masses having the same colour with respect to the
bicolouration of the Dynkin diagram. For the case of -affine Toda field
theory we compute explicitly the spectrum of all higher boundary bound states.
The complete set of states constitutes a closed bootstrap.Comment: 16 p., Late
Evaluating Sustainable Aspects of Hazardous Waste Remediation
The main objective of the research presented herein is to be a major contributor to the current international initiative to advance sustainability assessments for remediation projects by integrating methodologies from the environmental economics and social science disciplines. More specifically, the study aims to address some of the knowledge gaps related to conducting a comprehensive sustainability assessment for a remediation project. These knowledge gaps include: (1) there are few studies that include sustainability assessments of the variety of techniques and technologies implemented during site characterization; (2) the majority of sustainable remediation publications and assessment tools focus on evaluating the environmental impact of a contaminated site’s life cycle and minimally, if at all, on related socio-economic impacts; and (3) the role of risk perception in stakeholder engagement has not been explored in existing sustainable remediation frameworks. Chapters 2 through 4 presents a societal cost analysis methodology to quantify global socio-economic impacts arising from cleanup activity by monetizing the emissions and energy consumption through the integration of the social cost of environmental metrics. The results of environmental footprint and life cycle assessment evaluations conducted at various stages throughout the project life cycle were used as the basis for the societal cost analysis. Chapter 5 presents a survey developed and implemented to identify risk perception factors that influenced residents’ level of participation in risk management activities conducted by the local health department. Based on the case study evaluations presented herein, it can be concluded that the integration of methodologies from the environmental economics and social science disciplines into existing sustainable remediation frameworks results in a more comprehensive evaluation of triple bottom line impacts, a reduction in emissions and resources consumed during site activities, efficient use of financial resources, and a maximization of benefits to stakeholders, in particular the community
The Gross-Neveu Model from String Theory
We study an intersecting D-brane model which at low energies describes
(1+1)-dimensional chiral fermions localized at defects on a stack of N_c
D4-branes. Fermions at different defects interact via exchange of massless
(4+1)-dimensional fields. At weak coupling this interaction gives rise to the
Gross-Neveu (GN) model and can be studied using field theoretic techniques. At
strong coupling one can describe the system in terms of probe branes
propagating in a curved background in string theory. The chiral symmetry is
dynamically broken at zero temperature and is restored above a critical
temperature T_c which depends on the coupling. The phase transition at T_c is
first order at strong coupling and second order at weak coupling.Comment: 32 pages, harvmac (b
Mass generation without phase coherence in the Chiral Gross-Neveu Model at finite temperature and small N in 2+1 dimensions
The chiral Gross-Neveu model is one of the most popular toy models for QCD.
In the past, it has been studied in detail in the large-N limit. In this paper
we study its small-N behavior at finite temperature in 2+1 dimensions. We show
that at small N the phase diagram of this model is {\it principally} different
from its behavior at . We show that for a small number of
fermions the model possesses two characteristic temperatures and
. That is, at small N, along with a quasiordered phase the
system possesses a very large region of precursor fluctuations
which disappear only at a temperature , substantially higher than the
temperature of Kosterlitz-Thouless transition.Comment: a factor 2 corrected. An extended discussion of similarities and
differences of low-N behavior of the chiral GN model and various models of
superconductivity is currently in preparation and will be presented in
additional articl
Dynamical correlations and quantum phase transition in the quantum Potts model
We present a detailed study of the finite temperature dynamical properties of
the quantum Potts model in one dimension.Quasiparticle excitations in this
model have internal quantum numbers, and their scattering matrix {\gf deep} in
the gapped phases is shown to take a simple {\gf exchange} form in the
perturbative regimes. The finite temperature correlation functions in the
quantum critical regime are determined using conformal invariance, while {\gf
far from the quantum critical point} we compute the decay functions
analytically within a semiclassical approach of Sachdev and Damle [K. Damle and
S. Sachdev, Phys. Rev. B \textbf{57}, 8307 (1998)]. As a consequence, decay
functions exhibit a {\em diffusive character}. {\gf We also provide robust
arguments that our semiclassical analysis carries over to very low temperatures
even in the vicinity of the quantum phase transition.} Our results are also
relevant for quantum rotor models, antiferromagnetic chains, and some spin
ladder systems.Comment: 18 PRB pages added correction
Haldane limits via Lagrangian embeddings
In the present paper we revisit the so-called Haldane limit, i.e. a
particular continuum limit, which leads from a spin chain to a sigma model. We
use the coherent state formulation of the path integral to reduce the problem
to a semiclassical one, which leads us to the observation that the Haldane
limit is closely related to a Lagrangian embedding into the classical phase
space of the spin chain. Using this property, we find a spin chain whose limit
produces a relativistic sigma model with target space the manifold of complete
flags U(N)/U(1)^N. We discuss possible other future applications of
Lagrangian/isotropic embeddings in this context.Comment: 29 pages, 2 figure
Bethe ansatz solution of the anisotropic correlated electron model associated with the Temperley-Lieb algebra
A recently proposed strongly correlated electron system associated with the
Temperley-Lieb algebra is solved by means of the coordinate Bethe ansatz for
periodic and closed boundary conditions.Comment: 21 page
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