Let
0
≤
T
:
L
p
(
Y
,
ν
)
→
L
q
(
X
,
μ
)
0 \leq T:{L^p}(Y,\nu ) \to {L^q}(X,\mu )
be a positive linear operator and let
|
|
T
|
|
p
,
q
||T|{|_{p,q}}
denote its operator norm. In this paper a method is given to compute
|
|
T
|
|
p
,
q
||T|{|_{p,q}}
exactly or to bound
|
|
T
|
|
p
,
q
||T|{|_{p,q}}
from above. As an application the exact norm
|
|
V
|
|
p
,
q
||V|{|_{p,q}}
of the Volterra operator
V
f
(
x
)
=
∫
0
x
f
(
t
)
d
t
Vf(x) = \int _0^x {f(t)dt}
is computed.