On James type constants and the normal structure in Banach spaces
نویسندگان
چکیده
منابع مشابه
The James and von Neumann-Jordan type constants and uniform normal structure in Banach spaces
Recently, Takahashi has introduced the James and von Neumann-Jordan type constants. In this paper, we present some sufficient conditions for uniform normal structure and therefore the fixed point property of a Banach space in terms of the James and von Neumann-Jordan type constants and the Ptolemy constant. Our main results of the paper significantly generalize and improve many known results in...
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We create a new family of Banach spaces, the James–Schreier spaces, by amalgamating two important classical Banach spaces: James’ quasi-reflexive Banach space on the one hand and Schreier’s Banach space giving a counterexample to the Banach–Saks property on the other. We then investigate the properties of these James–Schreier spaces, paying particular attention to how key properties of their ‘a...
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چکیده شخصیت به مجموعه عوامل روانی، عقلی، احساسی، و فیزیکی تشکیل دهنده یک فرد اطلاق میشود، خصوصا فرد ازدیدگاه دیگران ( مرجع). تدابیر یاد گیری سعی در اگاهی از اقدامات زبان اموزان موفق زبان دوم یا یک زبان بیگانه را دارد که توسط خود زبان اموزان گزارش میشود،یا حین یادگیری زبان دوم یا زبان بیگانه از انها قابل مشاهده است( روبین و وندن 1987). همچنین تدابیر ارتباطی به زبان اموزان کمک می کند تا بر مشکلا...
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We obtained the estimates of Normal structure coefficient N(X) by NeumannJordan constant CNJ(X) of a Banach space X and found that X has uniform normal structure if CNJ(X) < (3 + √ 5)/4. These results improved both Prus’ [6] and Kato, Maligranda and Takahashi’s [4] work.
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Let X be a normed linear space, and let S(X) = fx 2 X : kxk = 1g be the unit sphere of X. Brodskii and Milman 1] introduced the following geometric concept: Deenition 1. A bounded, convex subset K of a Banach space X is said to have normal structure if every convex subset H of K that contains more than one point contains a point x 0 2 H, such that supfkx 0 ? yk : y 2 Hg < d(H); where d(H) = sup...
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ژورنال
عنوان ژورنال: Mathematical Inequalities & Applications
سال: 2020
ISSN: 1331-4343
DOI: 10.7153/mia-2020-23-26