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Remarks on the geometrical properties of semiclassically quantized strings
We discuss some geometrical aspects of the semiclassical quantization of string solutions in type IIB Green–Schwarz action on ADS5xS5 We concentrate on quadratic fluctuations around classical configurations, expressing the relevant differential operators in terms of (intrinsic and extrinsic) invariants of the background geometry. The aim of our exercise is to present some compact expressions encoding the spectral properties of bosonic and fermionic fluctuations. The appearing of non-trivial structures on the relevant bundles and their role in concrete computations are also considered. We corroborate the presentation of general formulas by working out explicitly a couple of relevant examples, namely the spinning string and the latitude BPS Wilson loop
Integrated forest management to prevent wildfires under Mediterranean environments
This review presents a multidisciplinary framework for integrating the ecological, regulatory, procedural and technical
aspects of forest management for fi res prevention under Mediterranean environments. The aims are to: i) provide a foreground of
wildfi re scenario; ii) illustrate the theoretical background of forest fuel management; iii) describe the available fuel management techniques
and mechanical operations for fi re prevention in forest and wildland-urban interfaces, with exemplifi cation of case-studies; iv)allocate fi re prevention activities under the hierarchy of forest planning. The review is conceived as an outline commentary discussion targeted to professionals, technicians and government personnel involved in forestry and environmental management
Algebra of Lax Connection for T-Dual Models
We study relation between T-duality and integrability. We develop the
Hamiltonian formalism for principal chiral model on general group manifold and
on its T-dual image. We calculate the Poisson bracket of Lax connections in
T-dual model and we show that they are non-local as opposite to the Poisson
brackets of Lax connection in original model. We demonstrate these calculations
on two specific examples: Sigma model on S(2) and sigma model on AdS(2).Comment: 24 pages, references adde
Integrated forest management to prevent wildfi res under mediterranean environments
This review presents a multidisciplinary framework for integrating the ecological, regulatory, procedural and technical aspects of forest management for fi res prevention under Mediterranean environments. The aims are to: i) provide a foreground of
wildfi re scenario; ii) illustrate the theoretical background of forest fuel management; iii) describe the available fuel management techniques and mechanical operations for fi re prevention in forest and wildland-urban interfaces, with exemplifi cation of case-studies; iv) allocate fi re prevention activities under the hierarchy of forest planning. The review is conceived as an outline commentary discussion targeted to professionals, technicians and government personnel involved in forestry and environmental managemen
First-principles derivation of the AdS/CFT Y-systems
We provide a first-principles, perturbative derivation of the AdS5/CFT4
Y-system that has been proposed to solve the spectrum problem of N=4 SYM. The
proof relies on the computation of quantum effects in the fusion of some loop
operators, namely the transfer matrices. More precisely we show that the
leading quantum corrections in the fusion of transfer matrices induce the
correct shifts of the spectral parameter in the T-system. As intermediate steps
we study UV divergences in line operators up to first order and compute the
fusion of line operators up to second order for the pure spinor string in
AdS5xS5. We also argue that the derivation can be easily extended to other
integrable models, some of which describe string theory on AdS4, AdS3 and AdS2
spacetimes.Comment: 45 pages, 5 figures; v2: minor additions, JHEP versio
One-loop spectroscopy of semiclassically quantized strings: bosonic sector
We make a further step in the analytically exact quantization of spinning string states in semiclassical approximation, by evaluating the exact one-loop partition function for a class of two-spin string solutions for which quadratic fluctuations form a non-trivial system of coupled modes. This is the case of a folded string in the SU(2) sector, in the limit described by a quantum Landau–Lifshitz model. The same applies to the full bosonic sector of fluctuations over the folded spinning string in AdS5 with an angular momentum J in S5. Fluctuations are governed by a special class of fourth-order differential operators, with coefficients being meromorphic functions on the torus, which we are able to solve exactly
Large-density field theory, viscosity, and "" singularities from string duals
We analyze systems where an effective large-N expansion arises naturally in
gauge theories without a large number of colors: a sufficiently large charge
density alone can produce a perturbative string ('tHooft) expansion. One
example is simply the well-known NS5/F1 system dual to , here viewed as a 5+1 dimensional theory at finite density. This model is
completely stable, and we find that the existing string-theoretic solution of
this model yields two interesting results. First, it indicates that the shear
viscosity is not corrected by effects in this system. For flow
perpendicular to the F1 strings the viscosity to entropy ratio take the usual
value , but for flow parallel to the F1's it vanishes as at low
temperature. Secondly, it encodes singularities in correlation functions coming
from low-frequency modes at a finite value of the momentum along the
directions. This may provide a strong coupling analogue of finite density
condensed matter systems for which fermionic constituents of larger operators
contribute so-called "" singularities. In the NS5/F1 example, stretched
strings on the gravity side play the role of these composite operators. We
explore the analogue for our system of the Luttinger relation between charge
density and the volume bounded by these singular surfaces. This model provides
a clean example where the string-theoretic UV completion of the gravity dual to
a finite density field theory plays a significant and calculable role.Comment: 28 pages. v2: added reference
Generalized cusp in AdS_4 x CP^3 and more one-loop results from semiclassical strings
We evaluate the exact one-loop partition function for fundamental strings
whose world-surface ends on a cusp at the boundary of AdS_4 and has a "jump" in
CP^3. This allows us to extract the stringy prediction for the ABJM generalized
cusp anomalous dimension Gamma_{cusp}^{ABJM} (phi,theta) up to NLO in
sigma-model perturbation theory. With a similar analysis, we present the exact
partition functions for folded closed string solutions moving in the AdS_3
parts of AdS_4 x CP^3 and AdS_3 x S^3 x S^3 x S^1 backgrounds. Results are
obtained applying to the string solutions relevant for the AdS_4/CFT_3 and
AdS_3/CFT_2 correspondence the tools previously developed for their AdS_5 x S^5
counterparts.Comment: 48 pages, 2 figures, version 3, corrected misprints in formulas 2.12,
B.86, C.33, added comment on verification of the light-like limi
On String S-matrix, Bound States and TBA
The study of finite J effects for the light-cone AdS superstring by means of
the Thermodynamic Bethe Ansatz requires an understanding of a companion 2d
theory which we call the mirror model. It is obtained from the original string
model by the double Wick rotation. The S-matrices describing the scattering of
physical excitations in the string and mirror models are related to each other
by an analytic continuation. We show that the unitarity requirement for the
mirror S-matrix fixes the S-matrices of both theories essentially uniquely. The
resulting string S-matrix S(z_1,z_2) satisfies the generalized unitarity
condition and, up to a scalar factor, is a meromorphic function on the elliptic
curve associated to each variable z. The double Wick rotation is then
accomplished by shifting the variables z by quarter of the imaginary period of
the torus. We discuss the apparent bound states of the string and mirror
models, and show that depending on a choice of the physical region there are
one, two or 2^{M-1} solutions of the M-particle bound state equations sharing
the same conserved charges. For very large but finite values of J, most of
these solutions, however, exhibit various signs of pathological behavior. In
particular, they might receive a finite J correction to their energy which is
complex, or the energy correction might exceed corrections arising due to
finite J modifications of the Bethe equations thus making the asymptotic Bethe
ansatz inapplicable.Comment: 77 pages, 6 figures, v2: the statement about the periodicity
condition for mirror fermions corrected; typos corrected; references added,
v3: misprints correcte
Review of AdS/CFT Integrability, Chapter II.2: Quantum Strings in AdS5xS5
We review the semiclassical analysis of strings in AdS5xS5 with a focus on
the relationship to the underlying integrable structures. We discuss the
perturbative calculation of energies for strings with large charges, using the
folded string spinning in an AdS3 subset of AdS5 as our main example.
Furthermore, we review the perturbative light-cone quantization of the string
theory and the calculation of the worldsheet S-matrix.Comment: 20 pages, see also overview article arXiv:1012.3982, v2: references
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