Tommaso Boccellari

5 Questions 6 Answers 0 Followers

Questions related from Tommaso Boccellari

When is there an homotopy taking a n-1 submanifold of R^n in a hyperplane?

Fix a C^0 automorphism f of R^n, a real number r. Then f({x_n=r}) is a topological n-1 submanifold of R^n. I ask if there is a real number s, a continuous function F : R^{n-1} x [0,1] ---> R^n...

25 April 2025 7,096 0 View

Where to find references about homotopy theory in sites?

I need results of homotopy, homology and cohomology theories, in the setting of Grothendieck sites. In particular I need the extension to sites of notions listed below: fibrations, bundles,...

17 February 2025 6,515 0 View

Are there conditions to be fulfilled by a site with terminal object and products to be a subsite of a cartesian closed site?

A site (C, J) is given such that category C has a terminal object and products. I am looking for conditions to be fulfilled by (C, J) ensuring the existence of a cartesian closed site (E, K) such...

20 October 2019 5,171 0 View

Where can I find references about real topological vector spaces such that all vector subspaces are closed?

My interest is in characterization of spaces described in the question. Clearly the interesting case is about infinite dimensional real vector spaces.

01 February 2019 1,651 8 View

I am looking for information about the set: local homeomorphisms of R^n / local diffeomorphisms of R^n. Is it a group? What about its structure?

Fix a positive integer n. We call local homeomorphism of R^n a function f:U--->R^n with: U open neighborhood of 0 \in R^n, f(0)=0, f injective continuous and open. We identify two local...

31 August 2016 2,565 10 View