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Hölder space

From Encyclopedia of Mathematics
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A Banach space of bounded continuous functions defined on a set of an -dimensional Euclidean space and satisfying a Hölder condition on .

The Hölder space , where is an integer, consists of the functions that are times continuously differentiable on (continuous for ).

The Hölder space , , where is an integer, consists of the functions that are times continuously differentiable (continuous for ) and whose -th derivatives satisfy the Hölder condition with index .

For bounded a norm is introduced in and as follows:

where , is an integer,

The fundamental properties of Hölder spaces for a bounded connected domain ( is the closure of ) are:

1) is imbedded in if , where and are integers, , . Here and the constant is independent of .

2) The unit ball of is compact in if . Consequently, any bounded set of functions from contains a sequence of functions that converges in the metric of to a function of .

References

[1] C. Miranda, "Partial differential equations of elliptic type" , Springer (1970) (Translated from Italian)


Comments

If, in the above, , then is the Hölder -semi-norm of on , i.e.

See Hölder condition, where this norm is denoted .

Hölder spaces play a role in partial differential equations, potential theory, complex analysis, functional analysis (cf. Imbedding theorems), etc.

How to Cite This Entry:
Hölder space. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=H%C3%B6lder_space&oldid=23330
This article was adapted from an original article by L.P. Kuptsov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article