294 reputation
36
bio website mai.liu.se/~halun
location Linköping, Sweden
age 44
visits member for 4 years, 5 months
seen Aug 28 at 6:01

Feb
19
comment Why do primes dislike dividing the sum of all the preceding primes?
(Nitpicking: The guy's name was Mertens, not Merten.)
Aug
22
awarded  Autobiographer
Aug
22
awarded  Yearling
Jun
25
awarded  Excavator
Sep
18
comment Examples of seemingly elementary problems that are hard to solve?
@suvrit: To the two different parenthesizations mentioned in the preceding sentence.
Sep
13
comment Geometric interpretation of matrix minors
"Lindström", to be precise.
Aug
13
comment What are the Poisson tensors for which hamiltonians are left invariant?
Your terminology seems a little nonstandard. $X_f$ is usually called the Hamiltonian vector field associated to $f$. When one speaks of "the Hamiltionian", this refers the the function $f$.
Feb
23
comment Elementary mathematical books
...and when I clicked it, I ended up at the Chern essay. (Perhaps not so surprising in hindsight, since both links point to the same URI.)
Feb
8
comment Reference for working with the implicit function theorem
Broken link. Hopefully this works better: fr.wikipedia.org/wiki/…
Feb
4
comment Does this formula have a rigorous meaning, or is it merely formal.
@Dick: I think the new name was introduced for marketing reasons, and is mainly used by the followers of David Hestenes.
Feb
3
comment Does this formula have a rigorous meaning, or is it merely formal.
...and by the way, I wish I could refer you to the book that a colleague of mine is writing, but unfortunately it is not finished yet: mai.liu.se/~anaxe/GMA.html
Feb
3
comment Does this formula have a rigorous meaning, or is it merely formal.
@Dick: GA is really just another name for Clifford algebras, and there are determinants everywhere if you do coordinate calculations in a Clifford algebra. For example, the highest graded part of the Clifford product of two (homogeneous) multivectors is the exterior product of those multivectors, and exterior product is related to determinants in a way that you're probably familiar with.
Jan
24
comment Volumes of n-balls: what is so special about n=5?
@unknown: Bob Palais, "$\pi$ Is Wrong", Opinion column in Math Intelligencer, Vol. 23, No. 3, 2001.
Jan
9
comment Bertrand theorem - central forces
Here's another reference that can be read on Google books: Boccaletti & Pucacco, Theory of orbits.
Jan
8
answered Bertrand theorem - central forces
Dec
8
comment Never appeared forthcoming papers
@Victor: Here are two examples by Flaschka: scholar.google.com/… (although this might be considered "cheating", since the Phys Rev B paper was probably labelled "II" instead of "I" by accident).
Nov
27
answered Nice Classes of Non-Closable Operators
Nov
26
awarded  Civic Duty
Nov
7
comment can the Newton's identities and Dodgson's condensations be proved by Gessel-Viennot's lemma?
"Submitted on 19 Oct 2010"; that's pretty good timing! ;)
Nov
7
comment can the Newton's identities and Dodgson's condensations be proved by Gessel-Viennot's lemma?
Gessel & Viennot give credit to the earlier results in their paper: "Arguments similar to the one of Lemma 5 have been used by Chaundy [3], Karlin and MacGregor [14], and Lindström [18]". The paper by Chaundy that they refer to is "The unrestricted plane partition" from 1932.