Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss

What's the name of this relation between metric spaces?

0 views
Skip to first unread message

Frank Wappler

unread,
Nov 26, 2009, 2:56:11 PM11/26/09
to

Given two metric spaces, (A, d) and (M, s),

such that there exist

a bijective map f: A <--> M, and

a positive real number k

by which for any two elements x and y of set A holds

s[ f[ x ], f[ y ] ] == k d[ x, y ] ...

... what's the name or technical term of this relation
between these two metric spaces, please?
("metric compatibility"?, "affinity"?, "___-morphism"?, ...).

Or are there perhaps names for some more general relations,
e.g. for (A, d) and (M, s) being pseudometric spaces,
or for f being an injective map?

Thanks a bunch,

Frank

Frank Wappler

unread,
Nov 26, 2009, 4:28:07 PM11/26/09
to

Allright, I just figured it out
(putting one's questions before the public is a marvellous way of
concentrating the mind/memory, isn't it? :) --

"scaled isometry"

see for instance
http://books.google.de/books?id=AKUlLbsZ12EC&pg=PA372&lpg=PA372&dq=%22scaled+isometry%22&source=bl&ots=uqiHZUsL-A&sig=iYK7fwIP9p9IfNrROUVkWDgfr24&hl=de&ei=0O0OS7HLMobFsgad_rGeAw&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAwQ6AEwAQ#v=onepage&q=%22scaled%20isometry%22&f=false

Thanks again,

Frank

G. A. Edgar

unread,
Nov 26, 2009, 5:53:19 PM11/26/09
to
In article
<0fcb7f4d-55a3-47ce...@v30g2000yqm.googlegroups.com>,
Frank Wappler <frwa...@gmail.com> wrote:

> Given two metric spaces, (A, d) and (M, s),
>
> such that there exist
>
> a bijective map f: A <--> M, and
>
> a positive real number k
>
> by which for any two elements x and y of set A holds
>
> s[ f[ x ], f[ y ] ] == k d[ x, y ] ...

This map is a "similitude" and the two spaces are "similar" ...
terminology from elementary geometry. This terminology is used in
fractal geometry, at least, as well as elementary geometry.

>
> ... what's the name or technical term of this relation
> between these two metric spaces, please?
> ("metric compatibility"?, "affinity"?, "___-morphism"?, ...).
>
> Or are there perhaps names for some more general relations,
> e.g. for (A, d) and (M, s) being pseudometric spaces,
> or for f being an injective map?
>
> Thanks a bunch,
>
> Frank
>

--
G. A. Edgar http://www.math.ohio-state.edu/~edgar/

0 new messages