1,560 research outputs found
The extended conformal theory of Luttinger systems
We describe the recently introduced method of algebraic bosonization of the
-dimensional Luttinger systems by discussing in detail the specific case
of the Calogero-Sutherland model, and mentioning the hard-core Bose gas. We
also compare our findings with the exact Bethe Ansatz results.Comment: 9 pages, plain Latex file, ,based on a talk given by S. Sciuto at the
II International Sakharov Conference on Physics, Moscow, Russia, 20-24 May 9
The extended conformal theory of the Calogero-Sutherland model
We describe the recently introduced method of Algebraic Bosonization of
(1+1)-dimensional fermionic systems by discussing the specific case of the
Calogero-Sutherland model. A comparison with the Bethe Ansatz results is also
presented.Comment: 12 pages, plain LaTeX, no figures; To appear in the proceedings of
the IV Meeting "Common Trends in Condensed Matter and High Energy Physics",
Chia Laguna, Cagliari, Italy, 3-10 Sep. 199
Anyonic Realization of the Quantum Affine Lie Superalgebra U_q(A(M,N)^{(1)})
We give a realization of the quantum affine Lie superalgebras U_q(A(M,N))^(1)
in terms of anyons defined on a one or two-dimensional lattice, the deformation
parameter q being related to the statistical parameter of the anyons by q
= exp(i\pi\nu). The construction uses anyons contructed from usual fermionic
oscillators and deformed bosonic oscillators. As a byproduct, realization
deformed in any sector of the quantum superalgebras U_q(A(M,N)) is obtained.Comment: 14p LaTeX Document (should be run twice
Non-perturbative studies of N=2 conformal quiver gauge theories
We study N=2 super-conformal field theories in four dimensions that
correspond to mass-deformed linear quivers with n gauge groups and
(bi-)fundamental matter. We describe them using Seiberg-Witten curves obtained
from an M-theory construction and via the AGT correspondence. We take
particular care in obtaining the detailed relation between the parameters
appearing in these descriptions and the physical quantities of the quiver gauge
theories. This precise map allows us to efficiently reconstruct the
non-perturbative prepotential that encodes the effective IR properties of these
theories. We give explicit expressions in the cases n=1,2, also in the presence
of an Omega-background in the Nekrasov-Shatashvili limit. All our results are
successfully checked against those of the direct microscopic evaluation of the
prepotential a la Nekrasov using localization methods.Comment: 56 pages, 7 figures, PdfLaTeX. v2: a few references added, version to
appear on Fortschritte der Physi
Modular and duality properties of surface operators in N=2* gauge theories
We calculate the instanton partition function of the four-dimensional N=2*
SU(N) gauge theory in the presence of a generic surface operator, using
equivariant localization. By analyzing the constraints that arise from
S-duality, we show that the effective twisted superpotential, which governs the
infrared dynamics of the two-dimensional theory on the surface operator,
satisfies a modular anomaly equation. Exploiting the localization results, we
solve this equation in terms of elliptic and quasi-modular forms which resum
all non-perturbative corrections. We also show that our results, derived for
monodromy defects in the four-dimensional theory, match the effective twisted
superpotential describing the infrared properties of certain two-dimensional
sigma models coupled either to pure N=2 or to N=2* gauge theories.Comment: 51 pages, v3: references added, typos fixed, footnote added, some
small changes in the text, appendix B streamlined. Matches the published
versio
Surface operators in 5d gauge theories and duality relations
We study half-BPS surface operators in 5d N=1 gauge theories compactified on
a circle. Using localization methods and the twisted chiral ring relations of
coupled 3d/5d quiver gauge theories, we calculate the twisted chiral
superpotential that governs the infrared properties of these surface operators.
We make a detailed analysis of the localization integrand, and by comparing
with the results from the twisted chiral ring equations obtain constraints on
the 3d and 5d Chern-Simons levels so that the instanton partition function does
not depend on the choice of integration contour. For these values of the
Chern-Simons couplings, we comment on how the distinct quiver theories that
realize the same surface operator are related to each other by Aharony-Seiberg
dualities.Comment: 39 pages. v2: A few sentences rephrased, references added, and typos
corrected. Matches version published in JHE
No habitat preference in mixed meadows and rocky bottoms for Mediterranean Labridae and Sparidae fish species
Fish species composition, abundance, diversity and niche breadth of Mediterranean littoral communities have been assessed for two types of habitat: rocky bottoms and mixed meadows of Posidonia oceanica (L.) Delile, 1813 and rocks. Labridae and Sparidae species have been considered to test differences in abundances between both habitats by means of underwater visual census. Data obtained suggests that these fish assemblages are very similar, and there are no significant differences in the niche breadth of both habitats. Differences in physical structure of the habitats are not enough to produce differences in the fish assemblages observed. A high fishing pressure in the study area may be removing the predator fish species, and consequently determining the species composition and abundance for rocky bottoms.Se ha estudiado la composición especÃfica, la abundancia, la diversidad y la amplitud de nicho de dos comunidades Ãcticas mediterráneas mediante censos visuales en dos tipos de hábitat: fondos rocosos y fondos mixtos de Posidonia oceanica (L.) Delile, 1813 y roca. Se han observado especies de lábridos y espáridos y no se han encontrado diferencias significativas en las variables analizadas de estas comunidades en ambos hábitats. Las diferencias en la estructura fÃsica de los dos tipos de hábitat no son suficientes para justificar la aparición de variaciones significativas en las comunidades Ãcticas estudiadas. Un factor condicionante puede ser la elevada tasa de presión pesquera, que elimina las especies depredadoras y determinarÃa la composición especÃfica y la abundancia de peces en los fondos rocosos.Instituto Español de OceanografÃ
Flight flexibility in strategic traffic planning: visualisation and mitigation use case
The concept of strategic traffic planning that takes into account changing airspace configurations, their capacity, and allows the quantification of flight flexibility is presented in this paper: the visualization of the results and an example of possible use. The concept is implemented through two deterministic optimization models. Here, we focus on the output of the models, which identifies the departure times, trajectories, flight flexibility and the list of saturated sector-hours throughout the day, based on the configurations used during the day. In order to make the output understandable to various stakeholders, we use a visualization tool and a set of performance indicators. The information on the saturated sectors, and their impact on flexibility (criticality index) is taken as an input in the example of mitigation action application by Air Navigation Service Providers, aimed at improving the situation. A mitigation strategy of increasing capacity of saturated airspace is implemented, and results show that the improvements in flexibility can be achieved
Anyonic Realization of the Quantum Affine Lie Algebra U_q(A_N)
We give a realization of quantum affine Lie algebra in
terms of anyons defined on a two-dimensional lattice, the deformation parameter
being related to the statistical parameter of the anyons by . In the limit of the deformation parameter going to one we recover
the Feingold-Frenkel fermionic construction of undeformed affine Lie algebra.Comment: 13p LaTeX Document (should be run twice
Impact on streams and sea water of a near-neutral drainage from a flooded mine in Sardinia, Italy
After mine closure and subsequent shutdown of the dewatering system, groundwater rebound led to drainage outflow from the Casargiu gallery (Montevecchio mine, SW Sardinia, Italy) since 1997. As compared with the first discharge, a very high contamination level still persists after almost 20 years of flushing. Mine drainage (20-70 L s-1; pH 6.0±0.2; Zn-Mg-Ca-SO4 composition) flows into the Rio Irvi. Abundant precipitation of amorphous Fe(III)-(oxy)hydroxides occurs. Moreover, sulfate-bearing green rust is observed to flocculate in the reach of the Rio Irvi where pH is still circumneutral. Water sampling along this stream shows a pH decrease from 6.0 to 4.0 and a significant removal of Fe (46%) and As (96%), while sulfate, Zn, Mn, Co, Ni and Cd show small variations downstream. Lead is initially adsorbed onto Fe(III)-(oxy)hydroxides, then desorbed as pH drops below 5.4. A conservative estimation of dissolved metals discharged into the Mediterranean Sea is significant (e.g. 900 kg day-1 Zn, 1.4 kg day-1 Cd, 5 kg day-1 Ni)
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