Sökning: "eigenvectors"

Visar resultat 1 - 5 av 16 uppsatser innehållade ordet eigenvectors.

1. 1. Dynamics at an exceptional point in an interacting quantum dot system

   Kandidat-uppsats, Lunds universitet/Fasta tillståndets fysik; Lunds universitet/Fysiska institutionen

   Författare :William Samuelson; [2022]
   Nyckelord :Physics and Astronomy;

   Sammanfattning : A fundamental postulate of quantum mechanics is that the Hamiltonian of a closed system is Hermitian, guaranteeing real-valued energies and conserved probabilities throughout the evolution of the system. However, for quantum systems where there is dissipation and crosstalk with the environment, such as a system of quantum dots connected to an environment of metallic leads, the dynamics of the system is instead generated by a non-Hermitian Liouvillian superoperator. LÄS MER

3. 2. Birefringence: Effects and Implications on In-Ice Radio Detection of High-Energy Neutrinos

   Master-uppsats, Uppsala universitet/Högenergifysik

   Författare :Nils Heyer; [2022]
   Nyckelord :Birefringence; Cosmic Neutrinos; In-ice radio propagation;

   Sammanfattning : The detection of high-energy neutrinos in the EeV range requires new detection techniques to cope with the small expected flux. The radio detection method, utilizing Askaryan emission, can be used to detect these neutrinos in polar ice. LÄS MER

4. 3. Damping Factor Analysis for PageRank

   Master-uppsats, Mälardalens universitet/Akademin för utbildning, kultur och kommunikation

   Författare :Fredrik Scheie; [2022]
   Nyckelord :PageRank; Damping factor; Probability matrix; Google matrix;

   Sammanfattning : The purpose of this thesis is to present research related to the damping factor in relation to the PageRank algorithm where a method of symbolic calculations is used to calculate eigenvalues, eigenvectors corresponding to the Google matrix in relation to both directed and undirected graphs. These graphs given comprise all the directed graphs up to four vertices and in addition the undirected graphs of five vertices are given in this thesis. LÄS MER

5. 4. Exploring and extending eigensolvers for Toeplitz(-like) matrices : A study of numerical eigenvalue and eigenvector computations combined with matrix-less methods

   Kandidat-uppsats, Uppsala universitet/Institutionen för informationsteknologi

   Författare :Martin Knebel; Fredrik Cers; Oliver Groth; [2022]
   Nyckelord :Toeplitz matrices; eigenvalue computation; eigenvector computation; matrix-less methods;

   Sammanfattning : We implement an eigenvalue solving algorithm proposed by Ng and Trench, specialized for Toeplitz(-like) matrices, utilizing root finding in conjunction with an iteratively calculated version of the characteristic polynomial. The solver also yields corresponding eigenvectors as a free bi-product. LÄS MER

7. 5. Factor Models for Futures Contracts to Improve Estimation of the Correlation Matrix

   Master-uppsats, Lunds universitet/Matematisk statistik

   Författare :Ellen Ek; [2022]
   Nyckelord :Correlation matrix; Hierarchical Principal Component Analysis; Factor Model; Clusters; Portfolio Optimization; Futures Contracts; Mathematics and Statistics;

   Sammanfattning : In this paper regularization of the correlation matrix between futures contracts is examined. With starting point in the recently established HPCA framework (Avellaneda, 2019), a couple of different extensions to the one-factor model is suggested. Extensions are made in terms of adjusting the model according to different cluster structures. LÄS MER