nifty.cl.library.light_cone_operator module

class LightConeOperator(domain, target, sigx)

Bases: Operator

Constructs a Light cone from a set of lightspeed parameters.

The resulting cone is defined as follows

\[\exp \left(- \frac{1}{2} \Re \left( \Delta \right)^2 \right)\]

with

\[\Delta = \sqrt{- \left(t^2 - \frac{x^\dagger C^{-1} x} {\sigma_x^2} \right)}\]

where t and x are the coordinates of the target space. Note that axis zero of the space is interpreted as the time axis. C denotes the input paramters of the operator and parametrizes the shape of the cone. sigx is the width of the asymptotic Gaussian in x necessary for discretization.

Parameters:

• domain (Domain, tuple of Domain or DomainTuple) – The domain of the input parameters of the light cone, the values of the lightspeed tensor.

• target (Domain, tuple of Domain or DomainTuple) – Output space on which the lightcone should be defined. The zeroth axis of this space is interpreted as the time axis.

• sigx (float) – Width of the Gaussian for the discretized representation of the cone.

__init__(domain, target, sigx)

apply(x)

Applies the operator to a Field, MultiField or Linearization.

Parameters:

x (nifty.cl.field.Field, nifty.cl.multi_field.MultiField,) – or nifty.cl.linearization.Linearization Input on which the operator shall act. Needs to be defined on domain. If x`is a :class:`nifty.cl.linearization.Linearization, apply returns a new nifty.cl.linearization.Linearization contining the result of the operator application as well as its Jacobian, evaluated at x.