I. A. Shevchuk

collaborators

2 papers

math.CA2024

Shape preserving approximation of periodic functions -- Conclusion

D. Leviatan, I. O. Shevchuk

We give here the final results about the validity of Jackson-type estimates in comonotone approximation of $2 π$ -periodic functions by trigonometric polynomials. For coconvex and th…

math.CA2014

New moduli of smoothness: weighted DT moduli revisited and applied

K. A. Kopotun, D. Leviatan, I. A. Shevchuk

We introduce new moduli of smoothness for functions $f \in L_{p} [- 1, 1] \cap C^{r - 1} (- 1, 1)$ , $1 \leq p \leq \infty$ , $r \geq 1$ , that have an $(r - 1)$ st locally absolutely continuous derivative…