TY - JOUR
AU - T. O. Kononovych
PY - 2008/08/25
Y2 - 2023/12/09
TI - Lower bound for the best approximations of periodic summable functions of two variables and their conjugates in terms of Fourier coefficients
JF - Ukrainsâ€™kyi Matematychnyi Zhurnal
JA - Ukr. Mat. Zhurn.
VL - 60
IS - 8
SE - Research articles
DO -
UR - https://umj.imath.kiev.ua/index.php/umj/article/view/3222
AB - In terms of Fourier coefficients, we establish lower bounds for the sum of norms and the sum of the best approximations by trigonometric polynomials for functions from the space L(Q²) and functions conjugate to them with respect to each variable and with respect to both variables, provided that these functions are summable.
ER -