Browsing Institutt for matematiske fag by Author "Berge, Stine Marie"

Now showing items 1-7 of 7

    • A Lichnerowicz estimate for the spectral gap of a sub-Laplacian 

      Berge, Stine Marie; Grong, Erlend (Journal article; Peer reviewed, 2019)
      Abstract: For a second order operator on a compact manifold satisfying the strong Hörmander condition, we give a bound for the spectral gap analogous to the Lichnerowicz estimate for the Laplacian of a Riemannian manifold. ...

    • Affine quantum harmonic analysis 

      Berge, Eirik; Berge, Stine Marie; Luef, Franz; Skrettingland, Eirik (Journal article; Peer reviewed, 2022)

    • The affine Wigner distribution 

      Berge, Eirik; Berge, Stine Marie; Luef, Franz (Peer reviewed; Journal article, 2022)
      We examine the affine Wigner distribution from a quantization perspective with an emphasis on the underlying group structure. One of our main results expresses the scalogram as (affine) convolution of affine Wigner ...

    • Analysis of the Wave Equation on the Disk 

      Fischbeck, Henrik Luthentun (Bachelor thesis, 2024)
      Musikalsk anologi har vært ansvarlig for mange generelle matematiske konsepter, som for eksempel bølgeligningen og spektraldekomonering. I denne bachelor oppgaven fokuserer heg på hvordan teorien av ubunnede operatorer ...

    • Convexity Properties of Harmonic Functions on Parameterized Families of Hypersurfaces 

      Berge, Stine Marie (Journal article; Peer reviewed, 2019)
      It is known that the L2L2-norms of a harmonic function over spheres satisfy some convexity inequality strongly linked to the Almgren’s frequency function. We examine the L2L2-norms of harmonic functions over a wide class ...

    • On the Three Ball Theorem for Solutions of the Helmholtz Equation 

      Berge, Stine Marie; Malinnikova, Eugenia (Journal article, 2021)
      Let $u_k$ be a solution of the Helmholtz equation with the wave number $k$, $\Delta u_k+k^2 u_k=0$, on (a small ball in) either $\mathbb{R}^n$, $\mathbb{S}^n$, or $\mathbb{H}^n$. For a fixed point $p$, we define ...

    • Quantitative Unique Continuation and Eigenvalue Bounds for the Laplacian 

      Berge, Stine Marie (Doctoral theses at NTNU;2021:285, Doctoral thesis, 2021)
      I denne avhandlingen skal vi studere flere aspekter ved laplaceoperatoren, spesielt med hensyn på egenverdier og egenfunksjoner. En stor del av avhandlingen er dedikert til kvantitativ unik utvidelse ulikheter for harmoniske ...