94 citations · 349 across the 46 of their papers we have counts for
5 papers · 1 filter
A degree preserving delta wye transformation with applications to 6-regular graphs and Feynman periods
Shannon Jeffries, Karen Yeats
We investigate a degree preserving variant of the -Y transformation which replaces a triangle with a new 6-valent vertex which has double edges to the vertices that had been in…
Column expansion identities and quadratic spanning forest identities
Melanie Fraser, Karen Yeats
Column expansion identities of determinants give a source of quadratic spanning forest polynomial identities and allow us determine the dimension of the space of certain quadratic…
Subdivergence-free gluings of trees
Xinle Dai, Jordan Long, Karen Yeats
A gluing of two rooted trees is an identification of their leaves and un-subdivision of the resulting 2-valent vertices. A gluing of two rooted trees is subdivergence free if it ha…
Algebraic Interplay between Renormalization and Monodromy
Dirk Kreimer, Karen Yeats
We investigate combinatorial and algebraic aspects of the interplay between renormalization and monodromies for Feynman amplitudes. We clarify how extraction of subgraphs from a Fe…
invariants of hourglass chains via quadratic denominator reduction
Oliver Schnetz, Karen Yeats
We introduce families of four-regular graphs consisting of chains of hourglasses which are attached to a finite kernel. We prove a formula for the invariant of these hourglas…