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5h
comment Can there be a numerical system in which logarithms can be expressed in terms of exponentials in closed form?
"people there just do not understand the question". Well, I don't mind confessing my thickness, but I don't understand the question either. I don't know what a "numerical field" is, and I don't know how you're going to extend the exponential/logarithm to that set. Except tautological answers like BenMcKay's, I just don't know what new "numbers" you'd expect. Just because you state "I wish I knew some system in which such and such formula is true" does not mean you ask a well-formed question and that everybody is supposed to understand its meaning.
1d
comment Eigenvalues of tridiagonal matrix
This question is really similar to your other one. Both are not research-level. You should consider posting elsewhere, like MathStackExchange which would be a better match.
2d
comment What will draw a shape for $L = \left\{ {\lambda \in \mathbb{C}:{s_4}(\lambda ) = {s_3}(\lambda )} \right\}$
A computer will.
2d
comment Analytic conjugacy of vanishing holonomy groups implies analytic conjugacy of foliations
The eigenvalues are invariants for vector fields, but the eigenratio is invariant for foliations.
Apr
30
reviewed Approve Injectivity/Surjectivity of $F_A :=\frac{d}{dt} +A(t) $ for a hyperbolic path of matrices $A(t)$ on $H^1 $
Apr
29
comment Calculus limit question
This question has already been closed. Please don't post it again.
Apr
29
reviewed Approve Are compactly supported continuous functions dense in the Continuous functions of Sobolev space?
Apr
29
reviewed Approve Shortest path in a weighted graph with coloured edges
Apr
29
revised Can the topological algebra of analytic functions be endowed with a norm that defines the natural topology?
added 30 characters in body
Apr
29
reviewed Approve Which varieties are flat degenerations of projective space?
Apr
29
reviewed Approve Shortest path in a weighted graph with coloured edges
Apr
29
answered Can the topological algebra of analytic functions be endowed with a norm that defines the natural topology?
Apr
29
comment Is there a bijection $f: N \times N \rightarrow U \subset N$ with $f(x,y)+f(u,v)=f(x+u,y+v)$ and $f(x,y) \cdot f(u,v)=f(x \cdot u, y \cdot v)$?
@John: I may be missing the point of your comment, but the arithmetics of rational numbers as ordered pairs of natural numbers is not the one you described because $\frac{a}{b}+\frac{c}{d}\neq\frac{a+c}{b+d}$ in general. Notice though that the (restricted) map described in the answer $(x,1)\mapsto x$ gives you the expected identification, for $\frac{x}{1}=x$.
Apr
27
reviewed Approve Can the matrix exponential be equal to the elementwise exponential
Apr
27
comment Can the matrix exponential be equal to the elementwise exponential
@FrancescoPolizzi: because $\exp 0 =1$...
Apr
27
comment Analytic conjugacy of vanishing holonomy groups implies analytic conjugacy of foliations
That's the same, by compactness of the exceptional divisor. Look, Epet, I think we should stop adding on comments like this, I'm even going to remove some of mine, and I encourage you to do the same. This is going nowhere, this site is not for step-by-step solving problems.
Apr
26
reviewed Approve Lyapunov exponents of Lorenz63 and Lorenz96 system
Apr
26
reviewed Approve Projections of orbifolds
Apr
26
comment Fréchet L-Spaces
It seems that Terry Pratchett also studied $L$-spaces ;)
Apr
25
comment Contour integral of non holomorphic but continuous functions
(Obviously there's a couple of typos in the first part: the formula should begin with $I_r=i\sum_{n=0}^\infty r^{n+1}…$, and the contributions come from $p+1=q$..)