Non-linear solutions of the renormalization group equations in the large-n limit

1977 ◽  
Vol 10 (7) ◽  
pp. 1175-1186 ◽  
Author(s):  
M Zannetti ◽  
C Di Castro
2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yohei Ema ◽  
Kyohei Mukaida ◽  
Jorinde van de Vis

Abstract We derive one- and two-loop renormalization group equations (RGEs) of Higgs-R2 inflation. This model has a non-minimal coupling between the Higgs and the Ricci scalar and a Ricci scalar squared term on top of the standard model. The RGEs derived in this paper are valid as long as the energy scale of interest (in the Einstein frame) is below the Planck scale. We also discuss implications to the inflationary predictions and the electroweak vacuum metastability.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
François Delduc ◽  
Sylvain Lacroix ◽  
Konstantinos Sfetsos ◽  
Konstantinos Siampos

Abstract In the study of integrable non-linear σ-models which are assemblies and/or deformations of principal chiral models and/or WZW models, a rational function called the twist function plays a central rôle. For a large class of such models, we show that they are one-loop renormalizable, and that the renormalization group flow equations can be written directly in terms of the twist function in a remarkably simple way. The resulting equation appears to have a universal character when the integrable model is characterized by a twist function.


2007 ◽  
Vol 8 (5) ◽  
pp. 449-464 ◽  
Author(s):  
C. H. Son ◽  
T. A. Shethaji ◽  
C. J. Rutland ◽  
H Barths ◽  
A Lippert ◽  
...  

Three non-linear k-ε models were implemented into the multi-dimensional computational fluid dynamics code GMTEC with the purpose of comparing them with existing linear k-ε models including renormalization group variations. The primary focus of the present study is to evaluate the potential of these non-linear models in engineering applications such as the internal combustion engine. The square duct flow and the backwards-facing step flow were two simple test cases chosen for which experimental data are available for comparison. Successful simulations for these cases were followed by simulations of an engine-type intake flow to evaluate the performance of the non-linear models in comparison with experimental data and the standard linear k-ε models as well as two renormalization group types. All the non-linear models are found to be an improvement over the standard linear model, but mostly in simple flows. For more complex flows, such as the engine-type case, only the cubic non-linear models appear to make a modest improvement in the mean flow but without any improvement in the root-mean-square values. These improvements are overshadowed by the stiffness of the cubic models and the requirements for smaller time steps. The contributions of each non-linear term to the Reynolds stress tensor are analysed in detail in order to identify the different characteristics of the different non-linear models for engine intake flows.


1992 ◽  
Vol 294 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Vipul Periwal

Sign in / Sign up

Export Citation Format

Share Document