SelfEnergy.h

/* Copyright 2017 Kristofer Björnson
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef COM_DAFER45_TBTK_SOLVER_SELF_ENERGY
#define COM_DAFER45_TBTK_SOLVER_SELF_ENERGY

#include "TBTK/BrillouinZone.h"
#include "TBTK/IndexedDataTree.h"
#include "TBTK/Property/InteractionVertex.h"
#include "TBTK/RPA/MomentumSpaceContext.h"
#include "TBTK/Solver/Solver.h"

namespace TBTK{
namespace Solver{

class SelfEnergy : public Solver{
public:
    SelfEnergy(
        const RPA::MomentumSpaceContext &momentumSpaceContext,
        const Property::InteractionVertex &interactionVertex
    );

    ~SelfEnergy();

    const RPA::MomentumSpaceContext& getMomentumSpaceContext() const;

    const Property::InteractionVertex& getInteractionVertex() const;

    void init();

    std::vector<std::complex<double>> calculateSelfEnergy(
        const Index &index,
        const std::vector<std::complex<double>> &energies
    );

    std::vector<std::complex<double>> calculateSelfEnergySelfConsistently(
        unsigned int numMatsubaraFrequencies,
        const std::vector<std::complex<double>> &energies
    );
private:
    const RPA::MomentumSpaceContext &momentumSpaceContext;

    const Property::InteractionVertex &interactionVertex;

    int *kMinusQLookupTable;

    void generateKMinusQLookupTable();

    template<bool useKPlusKLookupTable>
    int getKMinusQLinearIndex(
        unsigned int meshIndex,
        const std::vector<double> &k,
        int kLinearIndex
    ) const;

    bool isInitialized;

    template<bool singleSelfEnergyEnergy>
    void selfEnergyMainLoop(
        const Index &index,
        const std::vector<std::complex<double>> &energies,
        std::vector<std::complex<double>> &result
    );
};

inline const RPA::MomentumSpaceContext& SelfEnergy::getMomentumSpaceContext(
) const{
    return momentumSpaceContext;
}

inline const Property::InteractionVertex& SelfEnergy::getInteractionVertex(
) const{
    return interactionVertex;
}

};  //End of namespace Solver
};  //End of namespace TBTK

#endif