seampy package

Submodules

seampy.amplitudes module

class seampy.amplitudes.NumericalAmplitude(theory, helconf=None, multiplicity=None)

NumericalAmplitude provides a callable object to compute scattering amplitudes.

To call provide a phase space point from the lips package.

import seampy, lips

# generate phase space point
oParticles = lips.Particles(6)
oParticles.fix_mom_cons()

# compute gauge or gravity amplitude: give helconf
oYMAmp = NumericalAmplitude(theory="YM", helconf="pmpmpm")
oYMAmp(oParticles)  # returns a complex number

# compute scalar amplitude: give multiplicity of phase space
oBSAmp = NumericalAmplitude(theory="BS", multiplicity=6)
oBSAmp(oParticles)  # returns a complex number

detJ(sol, oParticles)

Numerical determinant of reduced Jacobian matrix Phi.

nCyc(sol)

Numerical cyclic Parke-Taylor-like factor.

nPfA(sol, oParticles)

Numerical pfaffian of reduced A.

nPfPsi(sol, oParticles)

Numerical pfaffian of reduced Psi.

nW1(sol, oParticles)

Numerical W1 (integrand for DF2 and CG).

solve_se(oParticles)

Interface to seampy.solver.solve_scattering_equations. Takes a phase space point as input.

seampy.integrands module

seampy.integrands.A(n)

A anti-symmetric matrix (reduced).

seampy.integrands.Cyc(n)

Parke-Taylor-like cyclic factor (reduced).

seampy.integrands.Phi(n)

SE Jacobian matrix (reduced).

seampy.integrands.Psi(n)

Psi anti-symmetric matrix (reduced).

seampy.integrands.W1(n)

DF2 and CG integrand (reduced).

seampy.solver module

seampy.solver.M(i, n=None)

Elimination theory matrix: i^th matrix in the recursion with n external legs. Default is i = n.

seampy.solver.V(n)

Elimination theory vector of variables.

seampy.solver.hms(n)

Scattering equations in polynomial form.

seampy.solver.mandelstams(n)

Mandelstam variables appearing in the polynomial scattering equations.

seampy.solver.numerical_coeffs(Mn, n, dict_ss)

Numerical coefficients of polynomial of order (n - 3)! obtianed from determinant of elimination theory matrix.

seampy.solver.punctures(n)

Punctures of the Riemann sphere.

seampy.solver.solve_scattering_equations(n, dict_ss)

Solves the scattering equations given multiplicity and mandelstams.

Module contents

Content as above.