3,972 reputation
11346
bio website bruno.stonek.com
location Montevideo, Uruguay
age 24
visits member for 3 years, 6 months
seen 1 hour ago

Math student in Université Paris 13.


21h
comment Question about Hopf-Rinow theorem
Have you checked do Carmo's "Riemannian geometry" book? The Hopf-Rinow theorem is there on pages 146-148, and he proves the equivalence of these two statements.
1d
comment Question about Hopf-Rinow theorem
Does ANII mean "Axiom of Numerability number II"? Also, I don't see where the question is. Are you asking why those two statements are equivalent?
1d
comment Suggestion about Algebraic Topology talk
You could look at R. Brown's "Topology and groupoids" book.
1d
revised What is the suspension used in the Freudenthal suspension theorem?
added 117 characters in body
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comment What is the suspension used in the Freudenthal suspension theorem?
@Rhoswyn: I think you are asking how to explicitly define $\Sigma f$ for an arrow $f$. I've included this in my answer.
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revised What is the suspension used in the Freudenthal suspension theorem?
added 90 characters in body
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comment What is the suspension used in the Freudenthal suspension theorem?
+1! I've expanded my answer to include some stuff that in particular explains how to obtain the suspension from two cones.
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revised What is the suspension used in the Freudenthal suspension theorem?
added 354 characters in body
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comment What is the suspension used in the Freudenthal suspension theorem?
You should remove the tag "fiber bundles"... They really don't appear in your question. Also, John is right (see my answer).
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comment What is the suspension used in the Freudenthal suspension theorem?
Does this answer your question or is there something that you'd like me to expand?
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answered What is the suspension used in the Freudenthal suspension theorem?
Apr
21
awarded  Popular Question
Apr
21
comment Is there a category of categories?
@user132181 Yes, sort of. See my first answer to the OP.
Apr
20
comment A few identities on differential forms
Have you checked Lee's "Introduction to Smooth Manifolds"? Whatever he proves he does it very thoroughly.
Apr
20
comment Equivalence of definitions for “normal extension” and how to lift isomorphisms to them
@HenrySwanson: You're welcome! I'm happy to hear it was useful. Also, Profs. Clark and Milne have other great sets of notes on their homepages, you might want to check them out.
Apr
20
answered Equivalence of definitions for “normal extension” and how to lift isomorphisms to them
Apr
15
comment Is there a category of categories?
@roman: true enough. I remember "The joy of cats" calling it a "quasicategory", although I don't think I even read how they defined that concept.
Apr
15
accepted When are generalized Severi-Brauer varieties trivial?
Apr
15
answered When are generalized Severi-Brauer varieties trivial?
Apr
15
comment Homology Whitehead theorem for non simply connected spaces
tom Dieck's Algebraic Topology book says (p. 498) that: In (20.1.5) one cannot dispense with the hypothesis that the spaces are simply connected. There exist, e.g., so-called acyclic complexes X with reduced homology groups vanishing but with non-trivial fundamental group. Moreover it is important that the isomorphism is induced by a map. The reference is to your (one version of) Whitehead's theorem. He then goes on to state and prove what you sketched in the comments.