# Tagged Questions

1answer
101 views

### Non-trivial Hausdorff measures for general metric spaces

For a metric space $(X,d)$ and a dimension function $\varphi:[0,\infty)\to[0,\infty)$ we can define a metric outer measure $H_\varphi$ which is $\varphi$-Hausdorff measure. Since it is a metric outer ...
1answer
158 views

### metric and measure on the projective space

Let $RP^n$ be the $n$-dim real projective space. I have the following four questions. What is the so called standard metric on $RP^n$? More generally, consider a metric space $M$ with an equivalent ...
1answer
132 views

### About measure theoretic interior and boundary

Reference:- Evans-Gariepy, Federer, other books and notes of geometric measure thoery. I just want to clarify whether these definitions of measure theoretic interior and boundary are correct. Given ...
1answer
107 views

### Is this map on a metric space upper-semi continuous?

Let $(X,d)$ be a metric space and $\mu$ a probability measure. Let $f(x)=\mu(B(x,r))$. Is this map upper semi continuous? I have some other assumptions since this is part of a larger proof but I'm ...
1answer
110 views

### Dimension invariance

Where can I find the Theorem of invariance of the dimension with diffeomorphisms? And about Between Homeomorphism? I also want to know about the Hausdorff dimension invariance what is deeper!
2answers
552 views

### Relations between various definitions of a Radon measure

The following various definitions of a Radon measure seem to be given for the Borel sigma algebra of different types of topological spaces: general, Hausdorff, locally compact, or locally compact ...