Upper semi-Fredholm property of operators and their modulus on Banach lattices
摘要
In the present manuscript, we present examples of regular upper semi-Fredholm (resp. non upper semi-Fredholm) operators on Banach lattices having non upper semi-Fredholm (resp. upper semi-Fredholm) modulus. We give also an example of a regular upper semi-Fredholm operator on Banach lattices with no modulus.