Sökning: "Padé approximant"

Hittade 5 avhandlingar innehållade orden Padé approximant.

1. 1. Multipoint Padé approximants used for piecewise rational interpolation and for interpolation to functions of Stieltjes' type

   Författare :Jan Gelfgren; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Continued fractions; Hardy space; Padé approximant; series of Stieltjes;

   Sammanfattning : A multipoint Padë approximant, R, to a function of Stieltjes1 type is determined.The function R has numerator of degree n-l and denominator of degree n.The 2n interpolation points must belong to the region where f is analytic,and if one non-real point is amongst the interpolation points its complex-conjugated point must too. LÄS MER

3. 2. Theoretical methods for the electronic structure and magnetism of strongly correlated materials

   Författare :Inka L. M. Locht; Igor Di Marco; Silke Biermann; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dynamical mean field theory DMFT ; Hubbard I approximation; strongly correlated systems; rare earths; lanthanides; photoemission spectra; ultrafast magnetization dynamics; analytic continuation; Padé approximant method; two-particle Green s functions; linear muffin tin orbitals LMTO ; density functional theory DFT ; cerium; stacking fault energy.; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : In this work we study the interesting physics of the rare earths, and the microscopic state after ultrafast magnetization dynamics in iron. Moreover, this work covers the development, examination and application of several methods used in solid state physics. The first and the last part are related to strongly correlated electrons. LÄS MER

4. 3. Electronic structure studies and method development for complex materials

   Författare :Andreas Östlin; Levente Vitos; Olle Eriksson; KTH; []
   Nyckelord :electronic structure theory; transition metals; method development;

   Sammanfattning : Over the years electronic structure theory has proven to be a powerful method with which one can probe the behaviour of materials, making it possible to predict properties that are difficult to measure experimentally. The numerical tools needed for these methods are always in need of development, since the desire to calculate more complex materials pushes this field forward. LÄS MER

5. 4. Electronic structure studies and method development for complex materials

   Författare :Andreas Östlin; Levente Vitos; László Udvardi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electronic structure theory; density functional theory; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : Over the years electronic structure theory has proven to be a powerful method with which one can probe the behaviour of materials, making it possible to describe and predict material properties. The numerical tools needed for these methods are always in need of development, since the desire to calculate more complex materials pushes this field forward. LÄS MER

7. 5. Theoretical and Computational Studies of Strongly Correlated Electron Systems : Dynamical Mean Field Theory, X-ray Absorption Spectroscopy and Analytical Continuation

   Författare :Johan Schött; Olle Eriksson; Igor Di Marco; Oscar Grånäs; Patrik Thunström; Tim Wehling; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : This thesis encompasses theoretical and computational studies of strongly correlated elec-tron systems. Understanding how electrons in solids interact with each other is of great im-portance for future technology and other applications. LÄS MER