Volume 36 • Number 1 • 2013   • Improved Converse Theorems and Fractional Moduli of Smoothness in Orlicz Spaces Ramazan Akgün Abstract. In the present work converse theorems of trigonometric approximation of functions and its fractional derivatives in certain Orlicz spaces are improved with respect to the fractional moduli of smoothness. An improved Marchaud inequality is also given. 2010 Mathematics Subject Classification: Primary: 46E30; Secondary: 41A10, 41A17, 41A25, 41A27, 42A10 Full text: PDF