The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We present some characterizations for the multiplication operators $$M_u$$ M u with finite range when acts on any Köthe sequence spaces. we also characterize its compactness and Fredholmness. Our characterizations are presented in terms of certain properties of the zeros set and the support of the symbol u.
The main purpose of this article is to introduce the concept of arithmetic continuity and arithmetic compactness in metric spaces and prove some interesting results related to these notions.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.