TY  - JOUR
A1  - Heins, Michael
A1  - Roth, Oliver
A1  - Waldmann, Stefan
T1  - Convergent star products on cotangent bundles of Lie groups
JF  - Mathematische Annalen
N2  - For a connected real Lie group G we consider the canonical standard-ordered star product arising from the canonical global symbol calculus based on the half-commutator connection of G. This star product trivially converges on polynomial functions on T\(^*\)G thanks to its homogeneity. We define a nuclear Fréchet algebra of certain analytic functions on T\(^*\)G, for which the standard-ordered star product is shown to be a well-defined continuous multiplication, depending holomorphically on the deformation parameter \(\hbar\). This nuclear Fréchet algebra is realized as the completed (projective) tensor product of a nuclear Fréchet algebra of entire functions on G with an appropriate nuclear Fréchet algebra of functions on \({\mathfrak {g}}^*\). The passage to the Weyl-ordered star product, i.e. the Gutt star product on T\(^*\)G, is shown to preserve this function space, yielding the continuity of the Gutt star product with holomorphic dependence on \(\hbar\).
KW  - Lie groups
KW  - star products
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324324
SN  - 0025-5831
VL  - 386
IS  - 1-2
ER  - 
TY  - JOUR
A1  - Kraus, Daniela
A1  - Moucha, Annika
A1  - Roth, Oliver
T1  - A sharp Bernstein–type inequality and application to the Carleson embedding theorem with matrix weights
JF  - Analysis and Mathematical Physics
N2  - We prove a sharp Bernstein-type inequality for complex polynomials which are positive and satisfy a polynomial growth condition on the positive real axis. This leads to an improved upper estimate in the recent work of Culiuc and Treil (Int. Math. Res. Not. 2019: 3301–3312, 2019) on the weighted martingale Carleson embedding theorem with matrix weights. In the scalar case this new upper bound is optimal.
KW  - Bernstein-type inequality
KW  - complex polynomials
KW  - Carleson embedding theorem
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270485
SN  - 1664-235X
VL  - 12
IS  - 1
ER  -