Department of Mathematics: Recent submissions
Now showing items 21-40 of 978
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Exceptional families of measures on Carnot groups
(Journal article; Peer reviewed, 2023)We study the families of measures on Carnot groups that have vanishing p -module, which we call Mp -exceptional families. We found necessary and sufficient Conditions for the family of intrinsic Lipschitz surfaces passing ... -
Symmetric Spaces Rolling on Flat Spaces
(Journal article; Peer reviewed, 2023)The objective of the current paper is essentially twofold. Firstly, to make clear the difference between two notions of rolling a Riemannian manifold over another, using a language accessible to a wider audience, in ... -
A robust solution strategy for the Cahn-Larché equations
(Journal article; Peer reviewed, 2023)In this paper we propose a solution strategy for the Cahn-Larché equations, which is a model for linearized elasticity in a medium with two elastic phases that evolve subject to a Ginzburg-Landau type energy functional. ... -
Portfolio Selection with a Rank-Deficient Covariance Matrix
(Journal article; Peer reviewed, 2024)In this paper, we consider optimal portfolio selection when the covariance matrix of the asset returns is rank-deficient. For this case, the original Markowitz’ problem does not have a unique solution. The possible solutions ... -
On the formulation of energy conservation in the eeKdV equation
(Journal article; Peer reviewed, 2024)The Korteweg-de Vries (KdV) equation is a well-known model equation for unidirectional shallow-water (long) surface waves. The equation includes dispersion and weak non-linearity. The derivation of the equation originates ... -
Well-Posedness for the Extended Schrödinger–Benjamin–Ono System
(Journal article; Peer reviewed, 2024) -
A finite mixture analysis of structural breaks in the G-7 gross domestic product series
(Journal article; Peer reviewed, 2023)In this paper we apply a clustering procedure to detect trend changes in macroeconomic data, focusing on the GDP time series for the G-7 countries. A finite mixture of regression models is considered to show different ... -
The Rectangle Complex of a Relation
(Journal article; Peer reviewed, 2023)We construct a simplicial complex, the rectangle complex of a relation R, and show that it is homotopy equivalent to the Dowker complex of . This results in a short and conceptual proof of functorial versions of Dowker’s ... -
Strongly interacting solitary waves for the fractional modified Korteweg-de Vries equation
(Journal article; Peer reviewed, 2023)We study one particular asymptotic behaviour of a solution of the fractional modified Korteweg-de Vries equation (also known as the dispersion generalised modified Benjamin-Ono equation): ∂tu + ∂x(−|D|αu + u3) = 0. The ... -
Determining homology of an unknown space from a sample
(Journal article; Peer reviewed, 2023)The homology of an unknown subspace of Euclidean space can be determined from the intrinsic Čech complex of a sample of points in the subspace, without reference to the ambient Euclidean space. More precisely, given a ... -
Sudden wave flooding on steep rock shores: a clear but hidden danger
(Journal article; Peer reviewed, 2024)It is shown that very steep coastal profiles can give rise to unexpectedly large wave events at the coast. We conduct a statistical analysis of runs from a nearshore Boussinesq-type model to demonstrate that under certain ... -
Local limit theorems for a directed random walk on the backbone of a supercritical oriented percolation cluster
(Journal article; Peer reviewed, 2023)We consider a directed random walk on the backbone of the supercritical oriented percolation cluster in dimensions d+1 with d≥3 being the spatial dimension. For this random walk we prove an annealed local central limit ... -
Asymptotic N -soliton-like solutions of the fractional Korteweg–de Vries equation
(Journal article; Peer reviewed, 2023)We construct N-soliton solutions for the fractional Korteweg–de Vries (fKdV) equation ∂tu−∂x(∣D∣αu−u2)=0, in the whole sub-critical range α∈(1/2,2). More precisely, if Qc denotes the ground state solution associated ... -
Profunctors Between Posets and Alexander Duality
(Journal article; Peer reviewed, 2023)We consider profunctors f : P |−→Q between posets and introduce their graph and ascent. The profunctors Pro(P, Q) form themselves a poset, and we consider a partition I F of this into a down-set I and up-set F, called a ... -
Bruk av algoritmisk tenkning og programmering som stillas for å understøtte læringsarbeidet i matematikk: Om opplevd mestring og mestringsklima i klasserommet.
(Master thesis, 2024-06-03)Mestring er et begrep som har blitt løftet fram med Fagfornyelsen og LK20. Dette prosjektet har gått ut på å undersøke mestringsklima i klasserommet og elevenes mestringsopplevelse når de arbeidet med mine egenutviklede, ... -
Specifying and identifying signs of ‘resonance’ in teachers’ professionalization processes as a condition for teacher change
(Journal article; Peer reviewed, 2023)Many studies on professionalization research deal with the question of how teachers actually learn or how teacher change occurs. In this context, Clarke and Hollingsworth (2002) describe a model for capturing teacher change ... -
The influence of ready-made tools on students’ learning by modelling with differential equations systems
(Journal article; Peer reviewed, 2023)This article discusses the role played by the tool when students learn about differential equations systems (DE) by modelling. The discussion was based on a three-case sub-study of an ongoing study of group-reports from ... -
Discussion about the role of teacher authority when making a transition into creative problem-solving in mathematics
(Journal article; Peer reviewed, 2023)When introducing a new kind of teaching activity into the classroom, the teacher cannot foresee whether the students will accept it or not. Even when the students do, there is a risk, that they might be neither able nor ... -
Modelling secondary circulations in stratified bi-directional flows: A potential mechanism for flux transfer from lower to upper fluid layers
(Journal article; Peer reviewed, 2023)Results are presented for new laboratory-scale numerical simulations of bi-directional stratified flows generated within an idealized trapezoidal sill-channel topography, focussing on the lateral (or secondary) flow structure ... -
How currents trigger extreme sea waves. The roles of Stokes drift, Eulerian return flow, and a background flow in the open ocean
(Journal article; Peer reviewed, 2024)A deterministic system of ocean surface waves and flow in the oceanic boundary layer is key to understanding the dynamics of the upper ocean. For the description of such complex systems, a higher-order shear-current modified ...