Volume 9, Issue 3 Marcel Hansmann An observation concerning boundary points of the numerical range Downloads Abstract PDF Full article PDF DOI { copied = true; setTimeout(() => copied = false, 2000) })" :aria-label="copied ? 'DOI copied' : 'Copy DOI'" :title="copied ? 'Copied' : 'Copy DOI'" > Find all available articles from these authors Marcel Hansmann Find more articles with the same keywords numerical range corners infinite curvature Find more articles with the same subject classes 47A10 47A12