2010/02/11 by Chung, Daewon, Pereyra, Cristina, Perez, Carlos
#42B20 #42B25 #46B70 #47B38 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Functional Analysis (math.FA)
paper · doi:10.48550/arxiv.1002.2396
We show that if an operator T is bounded on weighted Lebesgue space L2(w) and obeys a linear bound with respect to the A2 constant of the weight, then its commutator [b,T] with a function b in BMO will obey a quadratic bound with respect to the A2 constant of the weight. We also prove that the kth-order commutator Tkb=[b,Tk-1b] will obey a bound that is a power (k+1) of the A2 constant of the weight. Sharp extrapolation provides corresponding Lp(w) estimates. The results are sharp in terms of the growth of the operator norm with respect to the Ap constant of the weight for all 1