uconf.wrappers.shifted_operad¶
Shifted operad construction with standard Koszul/sign-representation twists.
For an operad P and integer shift d, this module implements a wrapper
ShiftedOperad(P, d) whose arity-n component is shifted by d (n - 1).
The symmetric-group action and composition follow the usual suspension-style
sign rules from standard operad references.
Classes
|
Factory for shifted operad components. |
- class uconf.wrappers.shifted_operad.ShiftedOperad(operad_cls, shift_degree)[source]¶
Bases:
UniqueRepresentationFactory for shifted operad components.
- Parameters:
operad_cls (OperadLike) – Base operad class (e.g.
LieorSurjection).shift_degree (int) – Integer
din the arity-dependent shiftd (n-1).
The construction uses the following conventions for homogeneous terms:
Symmetric action twist by
sgn(sigma)^d.Composition twist
(-1)^(d * ((i-1)(n-1) + (m-1)|y|))withm = arity(x),n = arity(y), and|y|in the base operad.
EXAMPLES:
sage: from sage.all import QQ sage: from uconf import Lie, ShiftedOperad sage: sLie = ShiftedOperad(Lie, 1) sage: x = sLie(2, QQ)((1,)) sage: x.arity() 2
- property connectivity: int¶
Connectivity of the shifted operad.
ShiftedOperad(P, d)(n)lives in degrees >= (k + d)*(n-1) where k is the connectivity of P, because the degree-shift byd*(n-1)raises the lower bound byd*(n-1).