Proper actions and proper invariant metrics
نویسندگان
چکیده
منابع مشابه
Proper actions and proper invariant metrics
We show that if a locally compact group G acts properly on a locally compact σ-compact space X, then there is a family of G-invariant proper continuous finite-valued pseudometrics which induces the topology of X. If X is, furthermore, metrizable, then G acts properly on X if and only if there exists a G-invariant proper compatible metric on X.
متن کاملConstructing Invariant Heine-borel Metrics for Proper G-spaces
We show that a group G acts properly and effectively on a locally compact and σ-compact metric space (X, d) if and only if there exists a compatible G-invariant Heine-Borel metric dp on X such that G is homeomorphic to a closed subgroup of the group of isometries Iso(X, dp).
متن کاملFrame-invariant proper-force
Here we try to find “the best joints for carving up” the phenomenon of accelerated-motion so as to obtain (i) the least need for extended-networks of synchronized-clocks as well as (ii) the greatest frame-independence. The acceleration four-vector’s invariant magnitude, and a number of other quantities from the traveler’s point of view, show promise for broadening student understanding (and per...
متن کاملProper Contractions and Invariant Subspaces
Let T be a contraction and A the strong limit of {T∗nTn}n≥1. We prove the following theorem: if a hyponormal contraction T does not have a nontrivial invariant subspace, then T is either a proper contraction of class 00 or a nonstrict proper contraction of class 10 for which A is a completely nonprojective nonstrict proper contraction. Moreover, its self-commutator [T∗,T ] is a strict contracti...
متن کاملProper gromov transforms of metrics are metrics
In phylogenetic analysis, a standard problem is to approximate a given metric by an additive metric. Here it is shown that, given a metric D defined on some finite set X and a non-expansive map f : X → R, the one-parameter family of the Gromov transforms D of D relative to f and ∆ that starts with D for large values of ∆ and ends with an additive metric for ∆ = 0 consists exclusively of metrics...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of the London Mathematical Society
سال: 2011
ISSN: 0024-6107
DOI: 10.1112/jlms/jdq091