Department of Mathematics
Recent Submissions
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Sparse Bayesian learning using TMB (Template Model Builder)
(Journal article; Peer reviewed, 2024)Sparse Bayesian Learning, and more specifically the Relevance Vector Machine (RVM), can be used in supervised learning for both classification and regression problems. Such methods are particularly useful when applied to ... -
Effects of a surface layer cross-flow and slope steepness on the rate of descent of dense water flows along a slope
(Journal article; Peer reviewed, 2024)The pathways and mixing in dense water overflows have been addressed in a range of numerical studies based on the DOME (Dynamics of Overflow Mixing and Entrainment) setup. These studies are motivated by overflows such as ... -
Applications of topological cyclic homology to algebraic K-theory
(Journal article; Peer reviewed, 2023) -
On connection algebras of symmetric spaces and reductive homogeneous spaces
(Doctoral thesis, 2024-10-25)Betrakt en glatt reell mangofldighet med en affin kobling. Denne koblingen former en algebra over vektorrommet av glatte seksjoner av tangentbunten. Vi kaller denne algebraen for koblingsalgebraen. Runge-Kutta-metoder ... -
Mathematical Modelling of Cellular and Evolutionary Processes in Changing Environments
(Doctoral thesis, 2024-10-25)Endrende miljøer er av sentral betydning i biologi, siden egenskapene og atferdene til alle organismer, fra bakterier til dyr, formes av hvor de lever. Dermed er organismer slik de er fordi de tidligere har tilpasset seg ... -
Comparing Structure and Dynamics of Transition Graphs by the Symmetric Difference Metric Over an Edge-Filtration
(Journal article; Peer reviewed, 2024)Transition graphs or transition diagrams, describing the rates and probabilities with which a system changes between discrete states, are common throughout the sciences. In many cases, parameterisations of transition graphs ... -
Simplicial Constructions in Applied Topology
(Doctoral thesis, 2024-10-16)I topologisk dataanalyse (TDA) analyserer man data ved å først konstruere et rom som fanger opp interessante egenskaper i dataen, og så studerer man topologien til dette rommet. Det er praktisk å jobbe med rom som har en ... -
Modelling of mixed-mechanism stimulation for the enhancement of geothermal reservoirs
(Journal article; Peer reviewed, 2024)Hydraulic stimulation is a critical process for increasing the permeability of fractured geothermal reservoirs. This technique relies on coupled hydromechanical processes induced through pressurized fluid injection into ... -
Non-Gaussian Ensemble Optimization
(Journal article; Peer reviewed, 2024)Ensemble-based optimization (EnOpt), commonly used in reservoir management, can be seen as a special case of a natural evolution algorithm. Stein’s lemma gives a new interpretation of EnOpt. This interpretation enables us ... -
Numerical Simulations of Viscous Fingering in Fractured Porous Media
(Journal article; Peer reviewed, 2024)The effect of heterogeneity induced by highly permeable fracture networks on viscous miscible fingering in porous media is examined using high-resolution numerical simulations. We consider the planar injection of a less ... -
Dispersive Wave Focusing on a Shear Current: Part 2—Nonlinear Effects
(Journal article; Peer reviewed, 2024)Continuing our recent work [Ellingsen et al., Water Waves (2024)] we investigate the influence of vertically sheared currents on the surface elevation as well as the kinematics of dispersively focusing wave groups up to ... -
The 11th Society of Petroleum Engineers Comparative Solution Project: Problem Definition
(Journal article; Peer reviewed, 2024)This article contains the description of, and call for participation in, the 11th Society of Petroleum Engineers Comparative Solution Project (the 11th SPE CSP, https://spe.org/csp). It is motivated by the simulation ... -
Stanley-Reisner ideals associated with triangulations
(Master thesis, 2024-06-03) -
The influence of an internship in South Africa on Norwegian preservice mathematics teachers' development of a professional identity
(Chapter, 2023)This paper reflects on how the future development of teacher identity by four Norwegian preservice secondary mathematics teachers may be influenced by a nine-week internship in South Africa. It was clear from interviews ... -
Unconditional uniqueness for the Benjamin-Ono equation
(Journal article, 2023)We study the unconditional uniqueness of solutions to the Benjamin–Ono equation with initial data in Hs, both on the real line and on the torus. We use the gauge transformation of Tao and two iterations of normal form ... -
Black-Litterman portfolio allocation using Local Gaussian Correlation
(Master thesis, 2024-04-27) -
Rolling Stiefel Manifolds Equipped with α-Metrics
(Journal article; Peer reviewed, 2023)We discuss the rolling, without slipping and without twisting, of Stiefel manifolds equipped with 𝛼-metrics, from an intrinsic and an extrinsic point of view. We, however, start with a more general perspective, namely, ... -
Shift modules, strongly stable ideals, and their dualities
(Journal article; Peer reviewed, 2023)We enrich the setting of strongly stable ideals (SSI): We introduce shift modules, a module category encompassing SSIs. The recently introduced duality on SSIs is given an effective conceptual and computational setting. ... -
A Bayesian Lasso based sparse learning model
(Journal article; Peer reviewed, 2023)The Bayesian Lasso is constructed in the linear regression framework and applies the Gibbs sampling to estimate the regression parameters. This paper develops a new sparse learning model, named the Bayesian Lasso Sparse ... -
Exploring Spline Based Models in glmmTMB
(Master thesis, 2024-06-03)In recent times the R-package glmmTMB has been extended to facilitate spline regression. In this thesis we implement spline based smoothers in glmmTMB-models and compare them to generalized additive models from mgcv and ...