Abstract :
Let P+ be the set of all non-negative operator monotone functions defined on [0,∞), and
put P−1
+ = {h : h−1 ∈ P+}. Then P+ · P−1
+ ⊂ P−1
+ and P−1
+ · P−1
+ ⊂ P−1
+ . For a function
˜h(t) and a strictly increasing function h we write ˜h h if ˜h ◦ h−1 is operator monotone. If
0 ˜h h and 0 ˜g g and if h ∈ P−1
+ and g ∈ P−1
+ ∪ P+, then ˜h ˜g h g. We will apply
this result to polynomials and operator inequalities. Let {ai }n
i=1 and {bi }n
i=1 be non-increasing
sequences, and put u+(t)= n
i=1(t −ai ) for t a1 and v+(t)= m
j=1(t −bj ) for t b1. Then
v+ u+ if m n and k
i=1bi k
i=1ai (1 k m): in particular, for a sequence {pn}∞n =0 of
orthonormal polynomials, (pn−1)+ (pn)+. Suppose 0
Keywords :
L?wner–Heinz inequality , Matrix order , Operator monotone function , Pick function , Orthogonal polynomial , majorization
Journal title :
Journal of Functional Analysis
Journal title :
Journal of Functional Analysis