Weak separation, positivity and extremal Yangian invariants
Abstract We classify all positive n-particle NkMHV Yangian invariants in N $$ \mathcal{N} $$ = 4 YangMills theory with n = 5k, which we call extremal because none exist for n > 5k. We show that this problem is equivalent to that of enumerating plane cactus graphs with k pentagons. We use the know...
Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
SpringerOpen
2019-09-01
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Series: | Journal of High Energy Physics |
Subjects: | |
Online Access: | http://link.springer.com/article/10.1007/JHEP09(2019)093 |