Zobrazeno 1 - 10
of 30
pro vyhledávání: '"Jacek Chmieliński"'
Autor:
Jacek Chmieliński, Moshe Goldberg
Publikováno v:
Linear Algebra and its Applications. 594:249-261
In this paper we extend our findings in [3] and answer further questions regarding continuity and discontinuity of seminorms on infinite-dimensional vector spaces.
10 pages
10 pages
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f676d03a7fa267bb7b110ba69258cb42
https://doi.org/10.1016/j.laa.2020.02.023
https://doi.org/10.1016/j.laa.2020.02.023
We introduce the notion of approximate smoothness in a normed linear space. We characterize this property and show the connections between smoothness and approximate smoothness for some spaces. As an application, we consider in particular the Birkhof
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::709405124e5752f84dc14a4eddac02ff
http://arxiv.org/abs/2109.11884
http://arxiv.org/abs/2109.11884
Autor:
Jacek Chmieliński, Paweł Wójcik
Publikováno v:
Journal of Mathematical Analysis and Applications. 461:625-640
In a real normed space X we consider an approximate symmetry of the Birkhoff orthogonality ⊥ B and establish its connections with some properties of the space X. Moreover, we introduce and study a new geometric constant for X, connected with the co
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::91539f7448016b2a595af097748ecedf
https://doi.org/10.1016/j.jmaa.2018.01.031
https://doi.org/10.1016/j.jmaa.2018.01.031
Publikováno v:
Linear Algebra and its Applications. 531:305-317
In a normed space we consider an approximate orthogonality relation related to the Birkhoff orthogonality. We give some properties of this relation as well as applications. In particular, we characterize the approximate orthogonality in the class of
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9a278cb7f0f52252351f2252e00bcd4c
https://doi.org/10.1016/j.laa.2017.06.001
https://doi.org/10.1016/j.laa.2017.06.001
We show that a real normed linear space endowed with the $$\rho $$ ρ -orthogonality relation, in general need not be an orthogonality space in the sense of Rätz. However, we prove that $$\rho $$ ρ -orthogonally additive mappings defined on some cl
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::74bda4041334c894fd1dbacb470a9240
http://hdl.handle.net/20.500.12128/15313
http://hdl.handle.net/20.500.12128/15313
Autor:
Jacek Chmieliński, Moshe Goldberg
Let $S$ be a seminorm on an infinite-dimensional real or complex vector space $X$. Our purpose in this note is to study the continuity and discontinuity properties of $S$ with respect to certain norm-topologies on $X$.
5 pages
5 pages
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9b593dc34cbdf53cd3ad6c4e86306134
http://arxiv.org/abs/1904.09423
http://arxiv.org/abs/1904.09423
Autor:
Jacek Chmieliński, Paweł Wójcik
Publikováno v:
Ulam Type Stability ISBN: 9783030289713
For real normed spaces, we consider the class of linear operators, approximately preserving or reversing the Birkhoff–James orthogonality. In particular we deal with stability problems.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5efd5996158f7734ec6ed7a9c8f524a9
https://doi.org/10.1007/978-3-030-28972-0_3
https://doi.org/10.1007/978-3-030-28972-0_3
Autor:
Jacek Chmieliński
Publikováno v:
Aequationes mathematicae. 89:97-105
Certain functional equations, related to the problem of characterization of metrics generated by norms, are considered. The solutions of these equations are strongly connected with additive and isometric mappings.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::df224736fd17ce9b45fa533e4fbf7acd
https://doi.org/10.1007/s00010-014-0275-5
https://doi.org/10.1007/s00010-014-0275-5
Autor:
Jacek Chmieliński
Publikováno v:
Aequationes mathematicae. 87:147-157
Let $${(X,\| \cdot \|)}$$ be a normed space. If $${\| \cdot \|_i}$$ is an equivalent norm coming from an inner product, then the original norm satisfies an approximate parallelogram law. Applying methods and results from the theory of stability of fu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a84f167aa5f05839839d254203d9bcc6
https://doi.org/10.1007/s00010-013-0193-y
https://doi.org/10.1007/s00010-013-0193-y
Autor:
Jacek Chmieliński, Paweł Wójcik
Publikováno v:
Banach Center Publications. 99:17-30
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::36b07821d53a89cb7647adf7176cb685
https://doi.org/10.4064/bc99-0-2
https://doi.org/10.4064/bc99-0-2