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Jan 25, 2020 at 23:29 comment added user142929 (2/2) where $f(x)=(x-a)^d$ is the polynomial in Casas-Alvero conjecture and $a\in k$, and I try to evoke/transfer conditions to state the equivalent form as the statement A suitable set of conditions for the functions $R_k(x)$ implies (say) $Q_1(x)=(x-a)^d$. This can be a naive strategy, my informal reasonings were of the kind taking products or realize those keywords in the conjecture: monic polynomials and degrees; and I don't know if an equivalent formulation in terms of rational functions can be exploited as advantage. My apologizes and thanks to the OP.
Jan 25, 2020 at 23:29 comment added user142929 (1/2) Do you know if the conjecture can be paraphrased in terms of certain rational functions satisfying certain conditions? I'm not a professional mathematician, but I wondered if you @FrançoisBrunault can/want tell me if it is potentially interesting, after I known this nice post from the professor. I was trying to propose informal conditions for $d-1$ rational functions $R_k(x)=\frac{P_k(x)}{Q_k(x)}$, thus $1\leq k\leq d-1$ to evoke an equivalent form of Casas-Alvero conjecture. My toy model are these $\frac{f'(x)}{f(x)},\frac{f''(x)}{f'(x)},\ldots ,\frac{f^{(d-1)}(x)}{f^{(d-2)}(x)}$,
Jul 31, 2017 at 2:51 comment added user49512 I think this squarely fails the 'anyone can understand it' requirement.
Oct 31, 2016 at 8:06 history edited Martin Sleziak CC BY-SA 3.0
added Wikipedia link
Apr 24, 2016 at 13:49 comment added Amr Oh ok I misunderstood the conjecture the first time I read it
Apr 24, 2016 at 13:29 comment added Amr Whaaat? I thought this was a trivially true statement
Nov 20, 2015 at 18:23 comment added Matheus @FrançoisBrunault: This paper has been withdrawn today (see arxiv.org/abs/1511.04932v2)
Nov 19, 2015 at 7:28 comment added François Brunault A proof of the conjecture is on arxiv arxiv.org/abs/1511.04932v1
Nov 13, 2015 at 16:27 comment added Andreas Thom @DenisSerre: The title was changed to "Towards the Casas-Alvero Conjecture".
Jul 31, 2015 at 19:49 comment added Denis Serre @AndreasThom. Not yet.
Jul 31, 2015 at 16:33 comment added Andreas Thom @DenisSerre. Did you check the proof?
Jul 31, 2015 at 14:51 comment added Denis Serre @Andreas. Strange that this paper deals only with $k={\mathbb C}$.
Jul 31, 2015 at 7:34 comment added Andreas Thom arxiv.org/abs/1504.00274
Jun 25, 2012 at 6:22 comment added js21 @François Brunault. Some months ago I asked this question mathoverflow.net/questions/94838/… with the Casas-Alvero conjecture in mind. It appeared from the answers that instead of the argument using scheme theory, the simpler Lefschetz principle ( proofwiki.org/wiki/Lefschetz_Principle_(First-Order) ) can be used. (answering to my question, Qiaochu Yuan also indicated an ultraproduct construction which is even simpler than the Lefschetz Principle, since no completeness result is used).
Jun 22, 2012 at 22:57 comment added François Brunault For those interested in this conjecture, here is what I believe the current state of knowledge on the conjecture : arxiv.org/abs/math/0605090 The first open case is $n=12$. Interestingly, the proofs in the known cases use scheme theory (over $\mathbf{Z}$).
Jun 22, 2012 at 20:39 history edited Denis Serre CC BY-SA 3.0
added 48 characters in body
Jun 22, 2012 at 20:38 comment added Denis Serre @Joel. Right! If $k$ is of finite characteristic $p$, then $X^{2p}+X^p$ does share a root with every derivative, but is not a monomial.
Jun 22, 2012 at 19:35 comment added Joël I guess $k$ must be of characteristic $0$
Jun 22, 2012 at 19:19 comment added Joël $k$ is any field?
Jun 22, 2012 at 6:39 history answered Denis Serre CC BY-SA 3.0