https://journalofconvexanalysis.com/articles/jca28015/
Hidden Convexity in the l_0 Pseudonorm | JCA
The so-called ℓ0 pseudonorm on Rd counts the number of nonzero components of a vector. It is well-known that the ℓ0 pseudonorm is not convex, as its Fenchel…
in thehiddenconvexitypseudonormjca