291 research outputs found
Finite volume form factors in the presence of integrable defects
We developed the theory of finite volume form factors in the presence of
integrable defects. These finite volume form factors are expressed in terms of
the infinite volume form factors and the finite volume density of states and
incorporate all polynomial corrections in the inverse of the volume. We tested
our results, in the defect Lee-Yang model, against numerical data obtained by
truncated conformal space approach (TCSA), which we improved by renormalization
group methods adopted to the defect case. To perform these checks we determined
the infinite volume defect form factors in the Lee-Yang model exactly,
including their vacuum expectation values. We used these data to calculate the
two point functions, which we compared, at short distance, to defect CFT. We
also derived explicit expressions for the exact finite volume one point
functions, which we checked numerically. In all of these comparisons excellent
agreement was found.Comment: pdflatex, 34 pages, many figure
SUSY sine-Gordon theory as a perturbed conformal field theory and finite size effects
We consider SUSY sine-Gordon theory in the framework of perturbed conformal field theory. Using an argument from Zamolodchikov, we obtain the vacuum structure and the kink adjacency diagram of the theory, which is cross-checked against the exact S-matrix prediction, first-order perturbed conformal field theory (PCFT), the NLIE method and truncated conformal space approach. We provide evidence for consistency between the usual Lagrangian description and PCFT on the one hand, and between PCFT, NLIE and a massgap formula conjectured by Baseilhac and Fateev, on the other. In addition, we extend the NLIE description to all the vacua of the theory. (C) 2003 Elsevier B.V. All rights reserved
Finite volume form factors in the presence of integrable defects
We developed the theory of finite volume form factors in the presence of integrable defects. These finite volume form factors are expressed in terms of the infinite volume form factors and the finite volume density of states and incorporate all polynomial corrections in the inverse of the volume. We tested our results, in the defect Lee-Yang model, against numerical data obtained by truncated conformal space approach (TCSA), which we improved by renormalization group methods adopted to the defect case. To perform these checks we determined the infinite volume defect form factors in the Lee-Yang model exactly, including their vacuum expectation values. We used these data to calculate the two point functions, which we compared, at short distance, to defect CFT. We also derived explicit expressions for the exact finite volume one point functions, which we checked numerically. In all of these comparisons excellent agreement was found. © 2014 The Authors
Exact Maximal Height Distribution of Fluctuating Interfaces
We present an exact solution for the distribution P(h_m,L) of the maximal
height h_m (measured with respect to the average spatial height) in the steady
state of a fluctuating Edwards-Wilkinson interface in a one dimensional system
of size L with both periodic and free boundary conditions. For the periodic
case, we show that P(h_m,L)=L^{-1/2}f(h_m L^{-1/2}) for all L where the
function f(x) is the Airy distribution function that describes the probability
density of the area under a Brownian excursion over a unit interval. For the
free boundary case, the same scaling holds but the scaling function is
different from that of the periodic case. Numerical simulations are in
excellent agreement with our analytical results. Our results provide an exactly
solvable case for the distribution of extremum of a set of strongly correlated
random variables.Comment: 4 pages revtex (two-column), 1 .eps figure include
Boundary form factors of the sinh-Gordon model with Dirichlet boundary conditions at the self-dual point
In this manuscript we present a detailed investigation of the form factors of
boundary fields of the sinh-Gordon model with a particular type of Dirichlet
boundary condition, corresponding to zero value of the sinh-Gordon field at the
boundary, at the self-dual point. We follow for this the boundary form factor
program recently proposed by Z. Bajnok, L. Palla and G. Takaks in
hep-th/0603171, extending the analysis of the boundary sinh-Gordon model
initiated there. The main result of the paper is a conjecture for the structure
of all n-particle form factors of two particular boundary operators in terms of
elementary symmetric polynomials in certain functions of the rapidity
variables. In addition, form factors of boundary "descendant" fields have been
constructedComment: 14 pages LaTex. Version to appear in J. Phys.
Towards Precision LSST Weak-Lensing Measurement - I: Impacts of Atmospheric Turbulence and Optical Aberration
The weak-lensing science of the LSST project drives the need to carefully
model and separate the instrumental artifacts from the intrinsic lensing
signal. The dominant source of the systematics for all ground based telescopes
is the spatial correlation of the PSF modulated by both atmospheric turbulence
and optical aberrations. In this paper, we present a full FOV simulation of the
LSST images by modeling both the atmosphere and the telescope optics with the
most current data for the telescope specifications and the environment. To
simulate the effects of atmospheric turbulence, we generated six-layer phase
screens with the parameters estimated from the on-site measurements. For the
optics, we combined the ray-tracing tool ZEMAX and our simulated focal plane
data to introduce realistic aberrations and focal plane height fluctuations.
Although this expected flatness deviation for LSST is small compared with that
of other existing cameras, the fast f-ratio of the LSST optics makes this focal
plane flatness variation and the resulting PSF discontinuities across the CCD
boundaries significant challenges in our removal of the systematics. We resolve
this complication by performing PCA CCD-by-CCD, and interpolating the basis
functions using conventional polynomials. We demonstrate that this PSF
correction scheme reduces the residual PSF ellipticity correlation below 10^-7
over the cosmologically interesting scale. From a null test using HST/UDF
galaxy images without input shear, we verify that the amplitude of the galaxy
ellipticity correlation function, after the PSF correction, is consistent with
the shot noise set by the finite number of objects. Therefore, we conclude that
the current optical design and specification for the accuracy in the focal
plane assembly are sufficient to enable the control of the PSF systematics
required for weak-lensing science with the LSST.Comment: Accepted to PASP. High-resolution version is available at
http://dls.physics.ucdavis.edu/~mkjee/LSST_weak_lensing_simulation.pd
Policy responses to problematic video game use: a systematic review of current measures and future possibilities
Background and aims: Empirical research into problematic video game playing suggests that overuse might cause functional and psychological impairments for a minority of gamers. Therefore, the need for regulation in the case of video games (whether governmental or self-imposed) has arisen but has only been implemented in a few countries around the world, and predominantly in Asia. This paper provides a systematic review of current and potential policies addressing problematic gaming.
Methods: After conducting a systematic search in the areas of prevention, treatment, and policy measures relating to problematic Internet and video game use, papers were selected that targeted problematic gaming policies (Nâ=â12; six in English and six in Korean). These papers served as the basis of this review.
Results: Policies were classified into three major groups: (i) policy measures limiting availability of video games (e.g., shutdown policy, fatigue system, and parental controls), (ii) measures aiming to reduce risk and harm (e.g., warning messages), and (iii) measures taken to provide help services for gamers. Beyond the attempt to classify the current and potential policy measures, the authors also tried to evaluate their efficiency theoretically and (if data were available) empirically.
Discussion and conclusions: Overall, it appears that although several steps have been taken to address problematic video game playing, most of these steps were not as effective as expected, or had not been evaluated empirically for efficacy. The reason for this may lie in the fact that the policies outlined only addressed or influenced specific aspects of the problem instead of using a more integrative approach
Generalized sine-Gordon/massive Thirring models and soliton/particle correspondences
We consider a real Lagrangian off-critical submodel describing the soliton
sector of the so-called conformal affine Toda model coupled to
matter fields (CATM). The theory is treated as a constrained system in the
context of Faddeev-Jackiw and the symplectic schemes. We exhibit the parent
Lagrangian nature of the model from which generalizations of the sine-Gordon
(GSG) or the massive Thirring (GMT) models are derivable. The dual description
of the model is further emphasized by providing the relationships between
bilinears of GMT spinors and relevant expressions of the GSG fields. In this
way we exhibit the strong/weak coupling phases and the (generalized)
soliton/particle correspondences of the model. The case is also
outlined.Comment: 22 pages, LaTex, some comments and references added, conclusions
unchanged, to appear in J. Math. Phy
Intraoperative and postoperative complications of gynecological laparoscopic interventions: incidence and risk factors
Purpose
The aims of this study were to determine the incidence of intraoperative and postoperative complications of laparoscopic gynecological interventions and to identify risk factors for such complications.
Methods
All patients who underwent laparoscopic interventions from September 2013 to September 2017 at the Department of Gynecology, Obstetrics and Reproductive Medicine, Saarland University Hospital were identified retrospectively using a prospectively compiled clinical database. Binary logistic regression analysis was used to identify independent risk factors for intra- and postoperative complications.
Results
Data from 3351 patients were included in the final analysis. Overall, 188 (5.6%) intraoperative and 219 (6.5%) postoperative complications were detected. On multivariate analysis, age [odds ratio (OR), 1.03; 95% confidence interval (CI) 1.01â1.04], surgery duration (OR, 1.02; 95% CI 1.02â1.03), carbon dioxide use (OR, 0.99; 95% CI 0.99â1.00), and surgical indication (all pââ€â0.01) were independent risk factors for intraoperative and duration of surgery (OR, 1.01; 95% CI 1.01â1.02; pââ€â0.01), carbon dioxide use (OR, 0.99; 95% CI 0.99â1.00; pââ€â0.01), hemoglobin drop (OR, 1.41; 95% CI 1.21â1.65; pââ€â0.01), and ASA status (pâ=â0.04) for postoperative complications.
Conclusion
In this large retrospective analysis with a generally low incidence of complications (5.6% intraoperative and 6.5% postoperative complications), a representative risk collective was identified: Patients agedâ>â38 years, surgery durationâ>â99 min, benign or malignant adnex findings were at higher risk for intraoperative and patients with surgery durationâ>â94 min, hemoglobin dropâ>â2 g/dl and ASA status III at higher risk for postoperative complications
Teaching undergraduate students gynecological and obstetrical examination skills: the patient's opinion
Introduction Our study assesses the patientsâ opinion about gynecological examination performed by undergraduate students
(UgSts). This assessment will be used in improving our undergraduate training program. A positive opinion would mean
a lower chance of a patient refusing to be examined by a tutor or student, taking into account vaginal examination (VE).
Materials and methods We performed a prospective cross-sectional survey on 1194 patients, consisting of outpatient and
inpatient at the departments of obstetrics and gynecology from November 2015 to May 2016. The questionnaire consisted
of 46 questions. Besides demographic data, we assessed the mindset of patients regarding the involvement of undergradu ate student (UgSt) in gynecological and obstetrical examinations. We used SPSS version 23 for the statistical analysis. For
reporting the data, we followed the STROBE statement of reporting observational studies.
Results The median age was 38 years having a median of one child. 34% presented due to obstetrical problems, 38% due to
gynecological complaints, and 19% due to known gynecological malignancies. Generally, we retrieved a positive opinion
of patients towards the involvement of students in gynecological and obstetrical examination under supervision in 2/3 of
the cases.
Conclusions There is no reason to exclude medical UgSts from gynecological and obstetrical examinations after obtaining
a written or oral consent
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