feynlag.lagrangian.Model

class feynlag.lagrangian.Model(name, gauge_groups=(), discrete_groups=(), fields=(), parameters=None, lagrangian=None)

A BSM model: symmetries + fields + parameters + Lagrangian.

All pipeline stages are lazy — nothing is solved at construction.

Pipeline surface:

• check_invariance() — gauge/discrete invariance of every term, hermiticity per sector, mass-dimension power counting;

• potential, vacuum — EWSB setup (L ⊃ −V);

• tadpoles(), solve_tadpoles() — vacuum conditions;

• mass_matrix() — real or charged scalar blocks at the vacuum;

• rotate() — register weak → physical Rotations;

• physical_lagrangian() — shifted, tadpole-substituted, rotated L;

• interactions(), feynman_rules() — vertex extraction.

__init__(name, gauge_groups=(), discrete_groups=(), fields=(), parameters=None, lagrangian=None)

Methods

__init__(name[, gauge_groups, ...])
check_anomalies([raise_on_failure])	Check that gauge anomalies cancel for the declared fermion content.
check_invariance([hermiticity, dimension, ...])	Check every Lagrangian term against every declared symmetry.
feynman_rules(fields[, sector, ...])	Feynman rules i × coefficient × ∏(multiplicity)! per vertex.
gauge_mass_matrix(gauge_components)	Gauge boson mass matrix from the (vacuum-evaluated) kinetic sector: M²_ab = ∂²L_kin,vac/∂A^a∂A^b.
gauge_vertices([groups, basis, simplifier, ...])	VVV and VVVV Vertex objects for the gauge self-couplings.
interactions(fields[, sector, ...])	Extract interaction coefficients from the physical Lagrangian.
mass_matrix(fields[, charged])	Scalar mass matrix at the vacuum for a block of fields.
physical_lagrangian([sector])	The Lagrangian in the physical basis: vacuum-shifted, tadpole solutions substituted, all registered rotations applied, expanded.
rotate(rotation)	Register a weak → physical Rotation.
solve_tadpoles(for_params)	Solve tadpoles for for_params; solutions are remembered and applied by mass_matrix() / physical_lagrangian(), and any InternalParameter among them gets defined.
spin_map([conjugate_map])	{symbol: spin} for every known component, fluctuation and rotated physical field (rotations propagate block spin; conjugate partners inherit the spin of the field they conjugate).
tadpoles()	Tadpole conditions {vev: ∂V/∂vev |_vacuum}.
validate([invariance, hermiticity, ...])	Run every applicable consistency check and aggregate the results.
vertices(fields[, sector, conjugate_map, ...])	Extract Vertex objects (typed by the closed Lorentz catalog) from the physical Lagrangian.

Attributes

potential	The scalar potential V (the Lagrangian stores −V).
scalars
vacuum
rotations	registered weak → physical Rotations, in application order