Search results for "Limit"

Eläköitymisen vaikutukset sukupolvien välisiin hyvinvointieroihin limittäisten sukupolvien malleissa : kjallisuuskatsaus malleihin ja aiempiin tutkim…

2015

Tämän työn tarkoitus on esitellä limittäisten sukupolvimallien ja kuluttajan käyttäytymisen teoreettiset perusteet sekä arvioida eläköitymisen merkitystä sukupolvien välisen hyvinvoinnin jakautumisessa aiemman empiirisentutkimuksen ja kirjallisuuden pohjalta. Eläköitymisen kokonaistaloudellisten muutosten tutkiminen edellyttää sukupolvittaista jaottelua. Tässä työssä tähän jaotteluun käytetyt menetelmät koostuvat sukupolvitilinpidosta ja numeerisista limittäisten sukupolvien malleista. Erityisesti limittäisten sukupolvien mallit kykenevät arvioimaan harjoitetun finanssipolitiikan kestävyyttä sukupolvien välisen hyvinvoinnin näkökulmasta. Mallien laskelmat ottavat huomioon eläköitymisen väli…

Valtion velkaantuminen ja hyvinvoinnin jakautuminen sukupolvien välillä : katsaus malleihin ja tuloksiin

2002

Limits to CO2-Neutrality of Burning Wood. (Review)

2016

Abstract Consumption of wood as a source of energy is discussed with respect to efficiency and restraints to ensure sustainability of the environment on the grounds of a simple analytical model describing dynamics of biomass accumulation in forest stands – a particular case of the well-known empirical Richards’ equation. Amounts of wood harvested under conditions of maximum productivity of forest land are presented in units normalised with respect to the maximum of the mean annual increment and used to determine the limits of CO2-neutrality. The ecological “footprint” defined by the area of growing stands necessary to absorb the excess amount of CO2 annually released from burning biomass is…

On the spectrum of semi-classical Witten-Laplacians and Schrödinger operators in large dimension

2005

We investigate the low-lying spectrum of Witten–Laplacians on forms of arbitrary degree in the semi-classical limit and uniformly in the space dimension. We show that under suitable assumptions implying that the phase function has a unique local minimum one obtains a number of clusters of discrete eigenvalues at the bottom of the spectrum. Moreover, we are able to count the number of eigenvalues in each cluster. We apply our results to certain sequences of Schrodinger operators having strictly convex potentials and show that some well-known results of semi-classical analysis hold also uniformly in the dimension.

New Invariant Domain Preserving Finite Volume Schemes for Compressible Flows

2021

We present new invariant domain preserving finite volume schemes for the compressible Euler and Navier–Stokes–Fourier systems. The schemes are entropy stable and preserve positivity of density and internal energy. More importantly, their convergence towards a strong solution of the limit system has been proved rigorously in [9, 11]. We will demonstrate their accuracy and robustness on a series of numerical experiments.

The Complex WKB Method

2019

In this chapter we shall study the exponential growth and asymptotic expansions of exact solutions of second-order differential equations in the semi-classical limit. As an application, we establish a Bohr-Sommerfeld quantization condition for Schrodinger operators with real-analytic complex-valued potentials.

Convergence of Measures

2020

One focus of probability theory is distributions that are the result of an interplay of a large number of random impacts. Often a useful approximation can be obtained by taking a limit of such distributions, for example, a limit where the number of impacts goes to infinity. With the Poisson distribution, we have encountered such a limit distribution that occurs as the number of very rare events when the number of possibilities goes to infinity (see Theorem 3.7). In many cases, it is necessary to rescale the original distributions in order to capture the behavior of the essential fluctuations, e.g., in the central limit theorem. While these theorems work with real random variables, we will a…

Spectral Asymptotics for More General Operators in One Dimension

2019

In this chapter, we generalize the results of Chap. 3. The results and the main ideas are close, but not identical, to the ones of Hager (Ann Henri Poincare 7(6):1035–1064, 2006). We will use some h-pseudodifferential machinery, see for instance Dimassi and Sjostrand (Spectral Asymptotics in the Semi-classical Limit, London Mathematical Society Lecture Note Series, vol 268. Cambridge University Press, Cambridge, 1999).

Hadronic light-by-light contribution to $(g-2)_\mu$ from lattice QCD with SU(3) flavor symmetry

2020

We perform a lattice QCD calculation of the hadronic light-by-light contribution to $(g-2)_\mu$ at the SU(3) flavor-symmetric point $m_\pi=m_K\simeq 420\,$MeV. The representation used is based on coordinate-space perturbation theory, with all QED elements of the relevant Feynman diagrams implemented in continuum, infinite Euclidean space. As a consequence, the effect of using finite lattices to evaluate the QCD four-point function of the electromagnetic current is exponentially suppressed. Thanks to the SU(3)-flavor symmetry, only two topologies of diagrams contribute, the fully connected and the leading disconnected. We show the equivalence in the continuum limit of two methods of computin…

Justification of point electrode models in electrical impedance tomography

2011

The most accurate model for real-life electrical impedance tomography is the complete electrode model, which takes into account electrode shapes and (usually unknown) contact impedances at electrode-object interfaces. When the electrodes are small, however, it is tempting to formally replace them by point sources. This simplifies the model considerably and completely eliminates the effect of contact impedance. In this work we rigorously justify such a point electrode model for the important case of having difference measurements ("relative data") as data for the reconstruction problem. We do this by deriving the asymptotic limit of the complete model for vanishing electrode size. This is s…