Tur\'an type converse Markov inequalities in $L^q$ on a generalized   Er\H{o}d class of convex domains
  P. Tur\'an was the first to derive lower estimations on the uniform norm of the derivatives of polynomials $p$ of uniform norm $1$ on the interval I:=[-1,1] and the disk D:=$\{z \in C~:~|z| \le 1\}$, under the normalization condition that the zeroes of the polynomial p in question all lie in I or D, resp. Namely, in 1939 he proved that with n:=deg p tending to infinity, the precise growth order of the minimal possible derivative norm is $\sqrt{n}$ for I and n for D.   Already the same year J. Er\H{o}d considered the problem on other domains. In his most general formulation, he extended Tur\'an's order n result on D to a certain general class of piecewise smooth convex domains. Finally, a decade ago the growth order of the minimal possible norm of the derivative was proved to be n for all compact convex domains.   Tur\'an himself gave comments about the above oscillation question in $L^q$ norm on D. Nevertheless, till recently results were known only for I, D and so-called R-circular domains.   Continuing our recent work, also here we investigate the Tur\'an-Er\H{o}d problem on general classes of domains. 
Polina Yu. Glazyrina, Szil\'ard Gy. R\'ev\'esz
math.CV