Blar i NTNU Open på forfatter "Luef, Franz"

Viser treff 21-34 av 34

    • Polyanalytic Toeplitz Operators: Isomorphisms, Symbolic Calculus and Approximation of Weyl Operators 

      Keller, Johannes; Luef, Franz (Peer reviewed; Journal article, 2021)
      We discuss an extension of Toeplitz quantization based on polyanalytic functions. We derive isomorphism theorem for polyanalytic Toeplitz operators between weighted Sobolev-Fock spaces of polyanalytic functions, which are ...

    • Rational Noncommutative Tori and Gabor Frames 

      Enstad, Ulrik Bo Rufus (Master thesis, 2016)
      A link between noncommutative geometry and time-frequency analysis is used to show that the TKNN equation violates existence results for Gabor frames with atoms in the Schwartz space. In particular, we use that the Schwartz ...

    • Sampling and periodization of generators of Heisenberg modules 

      Jakobsen, Mads Sielemann; Luef, Franz (Journal article; Peer reviewed, 2019)
      This paper considers generators of Heisenberg modules in the case of twisted group C∗-algebras of closed subgroups of locally compact abelian (LCA) groups and how the restriction and/or periodization of these generators ...

    • Solitons of general topological charge over noncommutative tori 

      Dabrowski, Ludwik; Jakobsen, Mads Sielemann; Landi, Giovanni; Luef, Franz (Peer reviewed; Journal article, 2021)
      We study solitons of general topological charge over noncommutative tori from the perspective of time-frequency analysis. These solitons are associated with vector bundles of higher rank, expressed in terms of vector-valued ...

    • The Algebraic Bivariant Connes-Chern Character 

      Austad, Are (Master thesis, 2017)
      In this thesis we present many properties of bivariant periodic cyclic homology with the purpose of then constructing two bivariant Connes-Chern characters from algebraic versions of Kasparov's KK-theory with values in ...

    • The Balian–Low theorem and noncommutative tori 

      Luef, Franz (Journal article; Peer reviewed, 2018)
      We point out a link between the theorem of Balian and Low on the non-existence of well-localized Gabor–Riesz bases and a constant curvature connection on projective modules over noncommutative tori.

    • The K-theory and Morita equivalence classes of noncommutative tori 

      Angelsen, Elias Klakken (Bachelor thesis, 2021)
      Når man studerer tidsfrekvensanalyse, møter man unitære translasjons- og modulasjonsoperatorer. Disse legger grunnlaget for en operatoralgebraisk tilnærming til emnet, og de studeres ofte gjennom ikke-kommutative tori, som ...

    • Time-Frequency Analysis Meets Quantum Harmonic Analysis 

      Skrettingland, Eirik (Doctoral theses at NTNU;2021:152, Doctoral thesis, 2021)
      The subject of this thesis is the study of quantum harmonic analysis and timefrequency analysis, and in particular the intersection of these two fields. Quantum harmonic analysis is studied abstractly both by obtaining new ...

    • Time-frequency analysis on the adeles over the rationals 

      Enstad, Ulrik Bo Rufus; Jakobsen, Mads Sielemann; Luef, Franz (Journal article; Peer reviewed, 2019)
      We show that the construction of Gabor frames in with generators in and with respect to time-frequency shifts from a rectangular lattice is equivalent to the construction of certain Gabor frames for over the adeles over ...

    • Twisted Convolution Algebras and Applications to Gabor Analysis 

      Austad, Are (Doctoral theses at NTNU;2021:155, Doctoral thesis, 2021)
      This thesis concerns several aspects of twisted convolution algebras, with a particular focus on problems arising in Gabor analysis. A significant portion of the thesis is dedicated to the study of Hilbert C -modules known ...

    • Uncertainty principle via variational calculus on modulation spaces 

      Dias, Nuno Costa; Luef, Franz; Prata, Joao Nuno (Journal article; Peer reviewed, 2022)
      We approach uncertainty principles of Cowling-Price-Heis-enberg-type as a variational principle on modulation spaces. In our discussion we are naturally led to compact localization operators with symbols in modulation ...

    • Uncertainty Principles in Time-Frequency Analysis – Fractals and Schrödinger Evolutions 

      Knutsen, Helge (Doctoral theses at NTNU;2023:162, Doctoral thesis, 2023)
      In this thesis we study two uncertainty principles from the perspective of timefrequency analysis. The first part, to which a significant portion is dedicated, is concerned with deriving an analog in the joint time-frequency ...

    • A Wiener Tauberian theorem for operators and functions 

      Luef, Franz; Skrettingland, Eirik (Peer reviewed; Journal article, 2021)
      We prove variants of Wiener's Tauberian theorem in the framework of quantum harmonic analysis, i.e. for convolutions between an absolutely integrable function and a trace class operator, or of two trace class operators. ...

    • Yang-Mills connections on quantum Heisenberg manifolds 

      Kang, Sooran; Luef, Franz; Judith, Packer (Journal article; Peer reviewed, 2020)
      We investigate critical points and minimizers of the Yang-Mills functional YM on quantum Heisenberg manifolds Dc µν, where the Yang-Mills functional is defined on the set of all compatible linear connections on finitely ...