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Jun
12
comment Chain morphism into a subcomplex homotopic to identity
@HSN Thank you for pointing out this typo. There is only one subcomplex involved.
May
22
comment Core for an unbounded operator.
Do you know a reference for the domain of $A^\ast A$ being a core of $A$?
Feb
9
comment What are single layer and double layer potentials?
This article does not provide very much information, and it does not explain single layer potentials. Where does that name come from?
Jan
29
comment Is this strengthening of paracompactness known?
Ok, that was a typo.
Oct
20
comment “Isomorphy” in mathematical texts
I have added an explanation.
Oct
20
comment “Isomorphy” in mathematical texts
I there is common agreement on that, can feel free to migrate it.
Oct
7
comment Term of partially ordered set with “levels”
Not necessarily, although in the application I have in mind, the sets $X_i$ are antichains. Thanks for making me aware of that.
Oct
2
comment Basis of vector space invariant under group action (of symmetric group)
What is $c_2$? However, indeed, such a basis might not exist, but how can this be shown?
Sep
10
comment Approximate root of $\alpha x - \beta y$ over $\mathbb Z$ except origin
@RobertIsrael Can you give more hints? I have no clue where to start with this.
Sep
10
comment Approximate root of $\alpha x - \beta y$ over $\mathbb Z$ except origin
Assuming $\beta > 0$, I see the equivalences. But what does it tell?
Sep
10
comment Approximate root of $\alpha x - \beta y$ over $\mathbb Z$ except origin
Has been a late night. Of course, the origin is excluded.
Jul
18
comment Canonical term for $\overline X / X$ where $X$ is a normed space.
This appears in the theory of Hilbert complexes, as quotient of the closure of the boundaries by the boundaries. More, generally, for Banach complexes see: link.springer.com/article/10.1007%2FBF02922133?LI=true
Sep
9
comment Formula for surface measure of spherical cap on $S^n$.
In the section 'hyperspherical cap', the wikipedia article gives a formula for the surface in terms of regularized incomplete beta functions. I wonder whether a single integral formula like for the volume, at the beginning of the same section, does exist.
Sep
8
comment Formula for surface measure of spherical cap on $S^n$.
I am specifically looking for formulas nicer than there.
Apr
5
comment Boundedness of a Solution Operator
@user17904: You need to show that for Sobolev space $H$ of sufficient regularity the trace from $H$ to $L^2(\partial\Omega)$ has closed range. Than a bounded right-inverse exists by functional analysis. Typically, you can prove surjectivity, say, by partition of unity, smoothing and an explicit construction.
Mar
7
comment pseudoinverse under change of norm
I have completely rewritten the question.
Mar
4
comment An variation of “Lk” in simplicial complexes
@StefanH.: Yes, thanks.
Feb
13
comment How can not-equals be expressed as an inequality for a linear programming model
It is intutive it does not work, because polyhedrons are convex and closed, while not-equals correspond to non-convex open regions.
Jan
29
comment Approaches to integrate $\int_0^1 \frac{x}{\sqrt{a+bx+cx^2}} dx$
Thanks, that got me on the right track.
Jan
27
comment If A $\subset S^n$ has spherical diameter < $\pi$, then $S^n - A$ contains a closed semisphere.
The original statement was blatantly wrong. I have editted the question into what I actually meant.