Browsing Institutt for matematiske fag by Journals "Proceedings of the American Mathematical Society"

Now showing items 1-11 of 11

    • 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. ...

    • Coefficient estimates for $H^p$ spaces with $0<p<1$ 

      Brevig, Ole Fredrik; Saksman, Eero (Peer reviewed; Journal article, 2020)
      Let C(k,p) denote the smallest real number such that the estimate |ak| ≤C(k,p)‖f‖Hp holds for every f(z) =∑n≥0anzn in the Hp space of the unit disc. We compute C(2,p)for0<p<1andC(3,2/3), and identify the functions attaining ...

    • COMPOSITION OPERATORS AND GENERALIZED PRIMES 

      Kouroupis, Athanasios (Peer reviewed; Journal article, 2023)

    • A direct construction of a full family of Whitham solitary waves 

      Ehrnstrom, Mats; Nik, Katerina; Walker, Christoph (Peer reviewed; Journal article, 2022)
      Starting with the periodic waves earlier constructed for the gravity Whitham equation, we parameterise the solution curves through relative wave height, and use a limiting argument to obtain a full family of solitary waves. ...

    • Exact large ideals of B(G) are downward directed. 

      Kaliszewski, Steve; Landstad, Magnus B.; Quigg, John (Journal article; Peer reviewed, 2016)
      We prove that if E and F are large ideals of B(G) for which the associated coaction functors are exact, then the same is true for E∩F. We also give an example of a coaction functor whose restriction to the maximal coactions ...

    • Exposing boundary points of strongly pseudoconvex subvarieties in complex spaces 

      Deng, Fusheng; Fornæss, John Erik; Wold, Erlend Fornæss (Journal article; Peer reviewed, 2018)
      We prove that all locally exposable points in a Stein compact in a complex space can be exposed along a given curve to a given real hypersurface. Moreover, the exposing map for a boundary point can be sufficiently close ...

    • An extension of Bohr's theorem 

      Brevig, Ole Fredrik; Kouroupis, Athanasios (Peer reviewed; Journal article, 2024)

    • Hochschild homology and trivial extension algebras 

      Bergh, Petter Andreas; Madsen, Dag Oskar (Journal article; Peer reviewed, 2017)
      We prove that if an algebra is either selfinjective, local or graded, then the Hochschild homology dimension of its trivial extension is infinite.

    • A note on the mean values of the derivatives of ζ/ζ 

      Chirre, Andrés (Peer reviewed; Journal article, 2022)
      Assuming the Riemann hypothesis, we obtain a formula for the mean value of the -derivative of , depending on the pair correlation of zeros of the Riemann zeta-function. This formula allows us to obtain new equivalences ...

    • Segal spaces, spans, and semicategories 

      Haugseng, Rune (Peer reviewed; Journal article, 2021)
      We show that Segal spaces, and more generally category objects in an -category , can be identified with associative algebras in the double -category of spans in . We use this observation to prove that “having identities” ...

    • The stable category of Gorenstein flat sheaves on a noetherian scheme 

      Christensen, Lars Winther; Estrada, Sergio; Thompson, Peder (Journal article; Peer reviewed, 2021)