Search results for "DST"
showing 10 items of 178 documents
Elementary Goldstone Higgs boson and dark matter
2015
We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrising the SU(4)/Sp(4) coset space. They acquire masses, and therefore become pseudo-Goldstone bosons, due to the embedding of the Yukawa and the electroweak gauge interactions that do not preserve the full SU(4) symmetry. At the one-loop order the top corrections dominate and align the vacuum in the direction where the Higgs is mostly a pseudo-Goldstone boson. Because of the perturbative and elementary nature of the theory, the quantum corrections are precisely calculable. The remaining pseudo-Goldstone boson …
Finite size spectrum of SU(N) principal chiral field from discrete Hirota dynamics
2016
Using recently proposed method of discrete Hirota dynamics for integrable (1+1)D quantum field theories on a finite space circle of length L, we derive and test numerically a finite system of nonlinear integral equations for the exact spectrum of energies of SU(N)xSU(N) principal chiral field model as functions of m L, where m is the mass scale. We propose a determinant solution of the underlying Y-system, or Hirota equation, in terms of determinants (Wronskians) of NxN matrices parameterized by N-1 functions of the spectral parameter, with the known analytical properties at finite L. Although the method works in principle for any state, the explicit equations are written for states in the …
Quantum stress tensor for extreme 2D Reissner-Nordström black holes
2004
Contrary to previous claims, it is shown that the expectation values of the quantum stress tensor for a massless scalar field propagating on a two-dimensional extreme Reissner-Nordstrom black hole are indeed regular on the horizon.
Hydrothermal liquefaction of wet biomass in batch reactors: Critical assessment of the role of operating parameters as a function of the nature of th…
2022
A scientometric analysis of articles published from 1986 to 2022 on batch hydrothermal liquefaction of microalgae, macroalgae, lignocellulosic biomass, sewage sludge and organic wastes in water was performed. We found that biocrude yield can be correlated with the kinetic severity factor (KSF) and scattering of experimental data increases in the supercritical region probably for uncertainty in the medium density affecting the kinetics of reactions involved in the process. The level of correlation and the yield increased when fast heating rates of the reactor, higher than 25 ◦C/min, were adopted. Energy recovery of biocrude obtained in fast heating experiments changes linearly with biocrude …
Which food for whom?
2015
From lack of food to food excess there are numerous different forms of malnutrition, caused by many determining factors. Improving the nutritional condition of populations therefore is a key task of public health care on a planetary level. It is also an economic challenge. The development of an agro-industrial system over the last sixty years has no doubt contributed to make foods safer, but it has also contributed to the consumption of products which are too fat and too sweet. As a consequence the innovation of healthier foods that are affordable has now become an important challenge. This challenge requires developing a new food engineering approach, notably improving the understanding of…
Jämförelse av webbtidningstexters kvantifierbara läsbarhet i Dagens nyheter och Hufvudstadsbladet
2006
Convergence of iterative methods in perturbation theory
1995
We discuss iterative KAM type methods for eigenvalue problems in finite dimensions. We compare their convergence properties with those of straight forward power series expansions.
Horizontal competition in multilevel governmental settings
2013
28 pages; Governments situated on the same level of a multi-level governmental system compete with each other as well as with governments placed higher or lower. This paper is concerned with horizontal competition only. It discusses both competition based on the mobility of agents and competition based on comparisons of performance across jurisdictions - i.e., yardstick competition. With regard to the first kind, the focus is on the capacity of governments and voters to decide policies in spite of the mobility of agents. Some attention is also given to non-standard mechanisms in which mobility is manipulated so as to change the structure of the electorate. The paper considers two forms of h…
How significant is yardstick competition among governments? Three reasons to dig deeper
2013
22 pages; The significance of yardstick competition among governments is now confirmed with regard to fiscal variables. This is an important result but the significance of the mechanism must also be sought in a context broader than that of fiscal federalism and without limitation to relations and processes fully observable. Three points are made. Even in the case of governments trying to mimic each other over a single variable, additional variables are involved in an important way. Yardstick competition can be latent without being ineffective. Its major effect, then, is to set bounds to the choices that office-holders could think of making. Finally, the mechanism is a hidden albeit essentia…