3. Renormalization group methods

This page ontains classes and methods related to the implementation of the renormalization group iteration.

Classes
class	RealTimeTransport::IteratedRG::CurrentKernel
	Defines the current kernel. More...
class	RealTimeTransport::IteratedRG::MemoryKernel
	Defines the RG memory kernel. More...

Enumerations
enum class	RealTimeTransport::IteratedRG::Order { Order::_2 = 2 , Order::_3 = 3 }
	Defines the order of the approximation. More...

Functions
IteratedRG::CurrentKernel	RealTimeTransport::computeCurrentKernel (const IteratedRG::MemoryKernel &K, const Propagator &propagator, int r, IteratedRG::Order order, SciCore::Real tMax, SciCore::Real errorGoal, int block=-1)
	Computes the current kernel for a given model.
IteratedRG::CurrentKernel	RealTimeTransport::computeCurrentKernel (const IteratedRG::MemoryKernel &K, const Propagator &propagator, int r, IteratedRG::Order order, SciCore::Real tMax, SciCore::Real errorGoal, tf::Executor &executor, int block=-1)
	Computes the current kernel for a given model in parallel.
SciCore::ChebAdaptive< SciCore::Real >	RealTimeTransport::computeCurrent (const IteratedRG::CurrentKernel &KCurrent, const Propagator &propagator, const Model::OperatorType &rho0)
	Computes the transient current for a given initial state.
IteratedRG::MemoryKernel	RealTimeTransport::computeMemoryKernel (const std::unique_ptr< Model > &model, IteratedRG::Order order, SciCore::Real tMax, SciCore::Real errorGoal)
	Computes the memory kernel for a given model.
IteratedRG::MemoryKernel	RealTimeTransport::computeMemoryKernel (const std::unique_ptr< Model > &model, IteratedRG::Order order, SciCore::Real tMax, SciCore::Real errorGoal, tf::Executor &executor)
	Computes the memory mernel for a given model in parallel.
Propagator	RealTimeTransport::computePropagator (const IteratedRG::MemoryKernel &memoryKernel)
	Computes the propagator corresponding to a given memory kernel.

Enumeration Type Documentation

Order

enum class RealTimeTransport::IteratedRG::Order

strong

Enumerator
_2	Two-loop approximation.
_3	Three-loop approximation.

Function Documentation

computeCurrentKernel() [1/2]

IteratedRG::CurrentKernel RealTimeTransport::computeCurrentKernel	(	const IteratedRG::MemoryKernel &	K,
		const Propagator &	propagator,
		int	r,
		IteratedRG::Order	order,
		SciCore::Real	tMax,
		SciCore::Real	errorGoal,
		int	block = -1 )

Computes the current kernel for a given model using the renormalization group iteration.

Parameters

K	The memory kernel for the model.
propagator	The propagator for the model.
r	Index of the reservoir \( r=0,1,\dots \)
order	The loop-order of the renormalization group iteration.
tMax	Maximum time until the current kernel is resolved.
errorGoal	Error goal of the current kernel computation.
block	Computes the complete current kernel if block==-1, otherwise computes only a single block with index block.

computeCurrentKernel() [2/2]

IteratedRG::CurrentKernel RealTimeTransport::computeCurrentKernel	(	const IteratedRG::MemoryKernel &	K,
		const Propagator &	propagator,
		int	r,
		IteratedRG::Order	order,
		SciCore::Real	tMax,
		SciCore::Real	errorGoal,
		tf::Executor &	executor,
		int	block = -1 )

Computes the current kernel for a given model using the renormalization group iteration in parallel.

Parameters

K	The memory kernel for the model.
propagator	The propagator for the model.
r	Index of the reservoir \( r=0,1,\dots \)
order	The loop-order of the renormalization group iteration.
tMax	Maximum time until the current kernel is resolved.
errorGoal	Error goal of the current kernel computation.
executor	An excecutor managing multiple threads.
block	Computes the complete current kernel if block==-1, otherwise computes only a single block with index block.

computeCurrent()

SciCore::ChebAdaptive< SciCore::Real > RealTimeTransport::computeCurrent	(	const IteratedRG::CurrentKernel &	KCurrent,
		const Propagator &	propagator,
		const Model::OperatorType &	rho0 )

Computes the transient current for a given initial state.

Parameters

KCurrent	The current kernel.
propagator	The propagator of the dynamics.
rho0	The initial state.

computeMemoryKernel() [1/2]

IteratedRG::MemoryKernel RealTimeTransport::computeMemoryKernel	(	const std::unique_ptr< Model > &	model,
		IteratedRG::Order	order,
		SciCore::Real	tMax,
		SciCore::Real	errorGoal )

Computes the memory kernel for a given model using the renormalization group iteration.

Parameters

model	The model for which the memory kernel is computed.
order	Order of the RG iteration.
tMax	Maximum time until the memory kernel is resolved.
errorGoal	Error goal of the memory kernel computation.

computeMemoryKernel() [2/2]

IteratedRG::MemoryKernel RealTimeTransport::computeMemoryKernel	(	const std::unique_ptr< Model > &	model,
		IteratedRG::Order	order,
		SciCore::Real	tMax,
		SciCore::Real	errorGoal,
		tf::Executor &	executor )

Computes the memory kernel for a given model using the renormalization group iteration in parallel.

Parameters

model	The model for which the memory kernel is computed.
order	Order of the RG iteration.
tMax	Maximum time until the memory kernel is resolved.
errorGoal	Error goal of the memory kernel computation.
executor	An excecutor managing multiple threads.

computePropagator()

Propagator RealTimeTransport::computePropagator

(

const IteratedRG::MemoryKernel &

memoryKernel

)

Computes the propagator corresponding to a given memory kernel. This is done my numerically solving the time-nonlocal master equation.

Parameters

memoryKernel

The memory kernel.