Browsing NTNU Open by Author "Galtung, Sondre Tesdal"
Now showing items 112 of 12

A 2dimensional shape optimization problem for tree branches
Bressan, Alberto; Galtung, Sondre Tesdal (Peer reviewed; Journal article, 2020)The paper is concerned with a shape optimization problem, where the functional to be maximized describes the total sunlight collected by a distribution of tree leaves, minus the cost for transporting water and nutrient ... 
A Convergent CrankNicolson Galerkin Scheme for the BenjaminOno Equation
Galtung, Sondre Tesdal (Master thesis, 2016)In this thesis we prove the convergence of a CrankNicolson type Galerkin finite element scheme for the initial value problem associated to the BenjaminOno equation. The proof is based on a recent result for a similar ... 
A Convergent Crank–Nicolson Galerkin Scheme for the Benjamin–Ono Equation
Galtung, Sondre Tesdal (Journal article; Peer reviewed, 2018)In this paper we prove the convergence of a Crank–Nicolson type Galerkin finite element scheme for the initial value problem associated to the Benjamin–Ono equation. The proof is based on a recent result for a similar ... 
Competition models for plant stems
Bressan, Alberto; Galtung, Sondre Tesdal; Reigstad, Audun; Ridder, Johanna (Peer reviewed; Journal article, 2020)The models introduced in this paper describe a uniform distribution of plant stems competing for sunlight. The shape of each stem, and the density of leaves, are designed in order to maximize the captured sunlight, subject ... 
Convergence Rates of a Fully Discrete Galerkin Scheme for the Benjamin–Ono Equation
Galtung, Sondre Tesdal (Chapter, 2018)We consider a recently proposed fully discrete Galerkin scheme for the Benjamin–Ono equation which has been found to be locally convergent in finite time for initial data in L 2 (R). By assuming that the initial data is ... 
Discretizations of Wave Equations and Applications of Variational Principles
Galtung, Sondre Tesdal (Doctoral theses at NTNU;2020:331, Doctoral thesis, 2020) 
Mean field limit for one dimensional opinion dynamics with Coulomb interaction and time dependent weights
BenPorat, Immanuel; Carrillo, José A.; Galtung, Sondre Tesdal (Journal article; Peer reviewed, 2024)The mean field limit with time dependent weights for a 1D singular case, given by the attractive Coulomb interactions, is considered. This extends recent results (Ayi and Duteil, 2021; Duteil, 2022) for the case of regular ... 
A numerical study of variational discretizations of the Camassa–Holm equation
Galtung, Sondre Tesdal; Grunert, Katrin (Peer reviewed; Journal article, 2021)We present two semidiscretizations of the Camassa–Holm equation in periodic domains based on variational formulations and energy conservation. The first is a periodic version of an existing conservative multipeakon method ... 
Optimal shapes for tree roots
Bressan, Alberto; Galtung, Sondre Tesdal; Sun, Qing (Journal article, 2022)The paper studies a class of variational problems, modeling optimal shapes for tree roots. Given a measure μ describing the distribution of root hair cells, we seek to maximize a harvest functional H , computing the ... 
A semidiscrete scheme derived from variational principles for global conservative solutions of a Camassa–Holm system
Galtung, Sondre Tesdal; Raynaud, Xavier (Peer reviewed; Journal article, 2021)We define a kinetic and a potential energy such that the principle of stationary action from Lagrangian mechanics yields a Camassa–Holm system (2CH) as the governing equations. After discretizing these energies, we use the ... 
Shock interactions for the BurgersHilbert equation
Bressan, Alberto; Galtung, Sondre Tesdal; Grunert, Katrin; Nguyen, Khai Tien (Peer reviewed; Journal article, 2022)This paper provides an asymptotic description of a solution to the BurgersHilbert equation in a neighborhood of a point where two shocks interact. The solution is obtained as the sum of a function with H2 regularity away ... 
Stumpons are nonconservative traveling waves of the Camassa–Holm equation
Galtung, Sondre Tesdal; Grunert, Katrin (Peer reviewed; Journal article, 2022)It is wellknown that by requiring solutions of the Camassa–Holm equation to satisfy a particular local conservation law for the energy in the weak sense, one obtains what is known as conservative solutions. As conservative ...