Essays about: "symmetric tensor"

Showing result 1 - 5 of 6 essays containing the words symmetric tensor.

  1. 1. Estimating Diffusion Tensor Distributions With Neural Networks

    University essay from Linköpings universitet/Algebra, geometri och diskret matematik; Linköpings universitet/Tekniska fakulteten

    Author : Rimaz Nismi; [2024]
    Keywords : Diffusion; Magnetic Resonance Imaging; MRI; Neural Networks; Optimal transport; Earth mover s distance; Sinkhorn distance;

    Abstract : Magnetic Resonance Imaging (MRI) is an essential healthcare technology, with diffusion MRI being a specialized technique. Diffusion MRI exploits the inherent diffusion of water molecules within the human body to produce a high-resolution tissue image. An MRI image contains information about a 3D volume in space, composed of 3D units called voxels. READ MORE

  3. 2. On the Interaction Between Electromagnetic, Gravitational, and Plasma Related Perturbations on LRS Class II Spacetimes

    University essay from Umeå universitet/Institutionen för fysik

    Author : Philip Semrén; [2021]
    Keywords : ;

    Abstract : In this thesis, we investigate the interaction between electromagnetic, gravitational, and plasma related perturbations on homogeneous and hypersurface orthogonal Locally Rotationally Symmetric (LRS) class II spacetimes. By using these spacetimes, which allow for the inclusion of a non-zero magnetic field, as backgrounds in a perturbative approach, we are able to see interactions between the electromagnetic and gravitational variables already to first order in the perturbations. READ MORE

  4. 3. Dissipative Perturbations on LRS Class II Cosmologies Using the 1+1+2 Covariant Split of Spacetime

    University essay from Umeå universitet/Institutionen för fysik

    Author : Philip Semrén; [2020]
    Keywords : ;

    Abstract : By including dissipative fluxes in the description, this thesis extends previous results regarding first order perturbations on homogeneous and hypersurface orthogonal locally rotationally symmetric (LRS) class II cosmologies using the 1 + 1 + 2 covariant split of spacetime. Whereas previous works consider perturbations of perfect fluid type, perturbations pertaining to heat flux and fluid viscosity are here studied with the aim to ascertain their effect on the evolution of the fluid vorticity. READ MORE

  5. 4. The Square-Root Isometry of Coupled Quadratic Spaces : On the relation between vielbein and metric formulations of spin-2 interactions

    University essay from Stockholms universitet/Fysikum; Stockholms universitet/Oskar Klein-centrum för kosmopartikelfysik (OKC)

    Author : Kocic Mikica B.; [2014]
    Keywords : modified gravity; bigravity; bimetric theory; square-root isometry;

    Abstract : Bimetric theory is an extension to general relativity that introduces a secondary symmetric rank-two tensor field. This secondary spin-2 field is also dynamical, and to avoid the Boulware-Deser ghost issue, the interaction between the two fields is obtained through a potential that involes the matrix square-root of the tensors. READ MORE

  6. 5. Tensor Rank

    University essay from Matematik och tillämpad matematik; Tekniska högskolan

    Author : Elias Erdtman; Carl Jönsson; [2012]
    Keywords : generic rank; symmetric tensor; tensor rank; tensors over finite fields; typical rank; generisk rang; symmetrisk tensor; tensorrang; tensorer över ändliga kroppar; typisk rang;

    Abstract : This master's thesis addresses numerical methods of computing the typical ranks of tensors over the real numbers and explores some properties of tensors over finite fields. We present three numerical methods to compute typical tensor rank. READ MORE