Simultaneous approximation by complex polynomials

Eman Samir Bhaya, Asmaa Raheem Hadi
2013 International Journal of Mathematical Analysis  
In this paper we prove the following theorem for simultaneous approximation in L ୮ spaces for p<1:Let m ∈ N. For any f ∈ A ୫ (॰) and n m, there exists a polynomial P ୬ of degree ݊, such that for all j=0,...,mwehave∥f ሺ୨ሻ െ Pn ሺ୨ሻ ‖ ୮ cሺpሻn ୨ି୫ E ୬ି୫ ሺf ሺ୫ሻ ሻ ୮ where cሺpሻ 0 depends on p butit isindependent of n and f. Here E ୬ ሺf ሺ୫ሻ ) =inf{∥ f ሺ୫ሻ െ P ∥ ୮ , P is polynomial of degree n}
doi:10.12988/ijma.2013.1869 fatcat:wgw5gglhbrgjxpor63xlb3moo4