Zobrazeno 1 - 10
of 26
pro vyhledávání: '"Katrin Fässler"'
Autor:
Katrin Fässler, Tuomas Orponen
Publikováno v:
Bulletin of the London Mathematical Society.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1ae2fd28b8cbb74706f4d3be2da409c7
https://doi.org/10.1112/blms.12844
https://doi.org/10.1112/blms.12844
Autor:
Katrin Fässler, Andrea Pinamonti
Publikováno v:
Mathematische Zeitschrift. 301:1983-2010
This note concernsLoomis–Whitney inequalitiesin Heisenberg groups$$\mathbb {H}^n$$Hn:$$\begin{aligned} |K| \lesssim \prod _{j=1}^{2n}|\pi _j(K)|^{\frac{n+1}{n(2n+1)}}, \qquad K \subset \mathbb {H}^n. \end{aligned}$$|K|≲∏j=12n|πj(K)|n+1n(2n+1),
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0ad46d747fb8e18cfd32f1a6a7d6548b
https://doi.org/10.1007/s00209-022-02968-y
https://doi.org/10.1007/s00209-022-02968-y
Autor:
Tuomas Orponen, Katrin Fässler
Publikováno v:
Journal de Mathématiques Pures et Appliquées. 153:30-113
Let $\mathbb{H}$ be the first Heisenberg group, and let $k \in C^{\infty}(\mathbb{H} \, \setminus \, \{0\})$ be a kernel which is either odd or horizontally odd, and satisfies $$|\nabla_{\mathbb{H}}^{n}k(p)| \leq C_{n}\|p\|^{-1 - n}, \qquad p \in \ma
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ece22bd616da991ee52d025d02ecb20d
https://doi.org/10.1016/j.matpur.2021.07.004
https://doi.org/10.1016/j.matpur.2021.07.004
Publikováno v:
International Mathematics Research Notices. 2022:17909-17975
Two definitions for the rectifiability of hypersurfaces in Heisenberg groups $\mathbb{H}^n$ have been proposed: one based on ${\mathbb{H}}$-regular surfaces and the other on Lipschitz images of subsets of codimension-$1$ vertical subgroups. The equiv
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b45b7d6cf665d3cc38bf26ef43486f78
https://doi.org/10.1093/imrn/rnab227
https://doi.org/10.1093/imrn/rnab227
Publikováno v:
Transactions of the American Mathematical Society
Transactions of the American Mathematical Society, American Mathematical Society, 2020, 373 (8), pp.5957-5996. ⟨10.1090/tran/8146⟩
Transactions of the American Mathematical Society, American Mathematical Society, 2020, 373 (8), pp.5957-5996. ⟨10.1090/tran/8146⟩
A Semmes surface in the Heisenberg group is a closed set $S$ that is upper Ahlfors-regular with codimension one and satisfies the following condition, referred to as Condition B. Every ball $B(x,r)$ with $x \in S$ and $0 < r < \operatorname{diam} S$
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8dc5594f61e50297d2f6b294ced7b3e7
https://doi.org/10.1090/tran/8146
https://doi.org/10.1090/tran/8146
Autor:
Katrin Fässler, Tuomas Orponen
Publikováno v:
Bulletin of the London Mathematical Society. 52:472-488
A theorem of Dorronsoro from the 1980s quantifies the fact that real-valued Sobolev functions on Euclidean spaces can be approximated by affine functions almost everywhere, and at all sufficiently small scales. We prove a variant of Dorronsoro's theo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5dd8ee547064e5c17276e3d9da91d632
https://doi.org/10.1112/blms.12341
https://doi.org/10.1112/blms.12341
Autor:
Katrin Fässler, Daniela Di Donato
This note concerns low-dimensional intrinsic Lipschitz graphs, in the sense of Franchi, Serapioni, and Serra Cassano, in the Heisenberg group $\mathbb{H}^n$, $n\in \mathbb{N}$. For $1\leq k\leq n$, we show that every intrinsic $L$-Lipschitz graph ove
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::911586531d5b184285023cd03d178841
http://urn.fi/URN:NBN:fi:jyu-202106083571
http://urn.fi/URN:NBN:fi:jyu-202106083571
Publikováno v:
Annali di Matematica Pura ed Applicata (1923 -). 199:147-186
We prove a Koebe distortion theorem for the average derivative of a quasiconformal mapping between domains in the sub-Riemannian Heisenberg group $${\mathbb {H}}^{1}$$. Several auxiliary properties of quasiconformal mappings between subdomains of $${
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a9f7c9405d3a5cc4bb1fd44c57729c8a
https://doi.org/10.1007/s10231-019-00871-8
https://doi.org/10.1007/s10231-019-00871-8
Publikováno v:
American Journal of Mathematics. 141:1087-1147
The purpose of this paper is to introduce and study some basic concepts of quantitative rectifiability in the first Heisenberg group $\mathbb{H}$. In particular, we aim to demonstrate that new phenomena arise compared to the Euclidean theory, founded
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f95718bfb1c6c2c04d87cfc1a7a85f6e
https://doi.org/10.1353/ajm.2019.0028
https://doi.org/10.1353/ajm.2019.0028
Autor:
Katrin Fässler, Enrico Le Donne
Publikováno v:
Geometriae Dedicata
This note is concerned with the geometric classification of connected Lie groups of dimension three or less, endowed with left-invariant Riemannian metrics. On the one hand, assembling results from the literature, we give a review of the complete cla
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f94c05ca50372b0e4944876a35acdc1a
https://pubmed.ncbi.nlm.nih.gov/33505086
https://pubmed.ncbi.nlm.nih.gov/33505086