203 research outputs found
Asymptotically Safe Quantum Field Theories in Perturbative Regime and Beyond
The range of topics covered in this thesis reflects the extent to which the tree of
Asymptotic Safety research has branched out in recent years. The thesis consists
of two parts, one dealing with pure particle models and one adding gravity to the
mix. Having roots in a 1996 paper by Reuter, Asymptotic Safety was for a long time
thought of as \u201conly\u201d a promising approach to quantum gravity. In 2014 an impor-
tant new branch was grafted to the tree when Litim and Sannino discovered first
examples of asymptotically safe quantum field theories structurally similar to the
Standard Model. In the first part of the thesis we work in perturbation theory and
with instanton calculus to extend the work of Litim and Sannino. The extension goes
in two directions. A more formal one studies the instanton effects in their model.
The other, more pragmatic one, seeks asymptotically safe minimal extensions of the
Standard Model. Despite being historically first, asymptotic safety in quantum grav-
ity context is studied after pure particle models here. The reasons are that quantum
gravity is a logical extension of \u201cbeyond the Standard Model\u201d particle physics, and
that it relies heavily on the less-known functional renormalization group. We will
show that a generic matter-gravity fixed point of the renormalization group flow al-
ways contains gravity-induced non-minimal matter-gravity interactions. This com-
putation will also demonstrate the practical necessity of dealing with background
independence in Asymptotic Safety, which is the final topic that we address
Adoption of Business Process Orientation Practices: Slovenian and Croatian Survey
Process orientation has been empirically linked to corporate performance. Several studies have shown that more process oriented companies perform better than less process oriented companies. Consequently, many researchers attempted to define what makes a company process oriented, which resulted in numerous frameworks and conceptualizations of process orientation. Based on concepts of business process orientation (BPO) the authors have developed and operationalised a concept of extended BPO to study its adoption in two countries, one EU member and one a candidate for EU membership (Slovenia and Croatia, respectively). Extensive field study has been carried out in these countries. The results of the analysis show that there are many statistically significant differences, namely companies in Slovenia have implemented process oriented practices to a higher degree than their counterparts in Croatia. The paper shows the main differences in BPO areas and practices.business process orientation, process orientation, maturity, empirical research, Croatia, Slovenia
Safe and free instantons
We investigate the instanton dynamics of asymptotically safe and free quantum
field theories featuring respectively controllable ultraviolet and infrared
fixed points. We start by briefly reviewing the salient points about the
instanton calculus for pure Yang Mills (YM) and QCD. We then move on to
determine the role of instantons within the controllable regime of the QCD
conformal window. In this region we add a fermion-mass operator and determine
the density of instantons per unit volume as function of the fermion mass.
Finally, for the first time, we extend the instanton calculus to asymptotically
safe theories.Comment: 34 pages, 15 figure
Image guided constitutive modeling of the brain tissue
Issued as final reportUnited States. Department of Health and Human Service
Quantum fields without wick rotation
We discuss the calculation of one-loop effective actions in Lorentzian spacetimes, based on a very simple application of the method of steepest descent to the integral over the field. We show that for static spacetimes this procedure agrees with the analytic continuation of Euclidean calculations. We also discuss how to calculate the effective action by integrating a renormalization group equation. We show that the result is independent of arbitrary choices in the definition of the coarse-graining and we see again that the Lorentzian and Euclidean calculations agree. When applied to quantum gravity on static backgrounds, our procedure is equivalent to analytically continuing time and the integral over the conformal factor
Mechanics and Computational Modeling of Pharmaceutical Tabletting Process
Reference Module in Materials Science and Materials EngineeringPharmaceutical Manufacturing Technology Centre (PMTC) in Irelan
Evaluation of pretreatment serum interleukin-6 and tumour necrosis factor alpha as a potential biomarker for recurrence in patients with oral squamous cell carcinoma
Background: Oral squamous cell carcinoma (OSCC) constitutes 3 percent of all cancers with predominant occurrence in middle aged and elderly males. Tumour recurrence worsens disease prognosis and decreases quality
of life in patients with OSCC. Proinflammatory cytokines such as interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α) have been suggested to play a certain role in variety of tumours. The aim of this study was to
investigate the relationship of pretreatment serum IL-6 and TNF-α levels on tumour recurrence in patients with
OSCC in order to identify potential biomarkers for the early detection of disease recurrence.
Material and Methods: The patients with newly diagnosed OSCC were treated and followed from the first visit
from November 2006 until January 2008. Serum IL-6 and TNF-α concentrations were measured. The records of
the patients were re-examined in July 2012 and data were recorded about cancer characteristics and tumour recurrence. Disease free survival was analyzed by Kaplan-Meier survival curves, log rank test and Cox proportional
hazards regression.
Results: Serum IL-6 was shown as an independent risk factor for tumour recurrence.
Conclusions: Pretreatment serum IL-6 concentration may be a useful biomarker for identification of OSCC patients with increased risk of the disease recurrence
In search of a UV completion of the standard model \u2014 378,000 models that don\u2019t work
Asymptotically safe extensions of the Standard Model have been searched for by adding vector-like fermions charged under the Standard Model gauge group and having Yukawa-like interactions with new scalar fields. Here we study the corresponding renormalization group \u3b2-functions to next and next-to-next to leading order in the perturbative expansion, varying the number of extra fermions and the representations they carry. We test the fixed points of the \u3b2-functions against various criteria of perturbativity to single out those that are potentially viable. We show that all the candidate ultraviolet fixed points are unphysical for these models: either they are unstable under radiative corrections, or they cannot be matched to the Standard Model at low energies
Assessment of intra- and inter-ventricular cardiac dyssynchrony in patients with repaired Tetralogy of Fallot: a cardiac magnetic resonance study
Using radiative magnetohydrodynamic simulations of the magnetized solar photosphere and detailed spectro-polarimetric diagnostics with the Fe I 6301.5 Å and 6302.5 Å photospheric lines in the local thermodynamic equilibrium approximation, we model active solar granulation as if it was observed at the solar limb. We analyze general properties of the radiation across the solar limb, such as the continuum and the line core limb darkening and the granulation contrast. We demonstrate the presence of profiles with both emission and absorption features at the simulated solar limb, and pure emission profiles above the limb. These profiles are associated with the regions of strong linear polarization of the emergent radiation, indicating the influence of the intergranular magnetic fields on the line formation. We analyze physical origins of the emission wings in the Stokes profiles at the limb, and demonstrate that these features are produced by localized heating and torsional motions in the intergranular magnetic flux concentrations
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