Post processing

The following functions can be invoked after a calculation has been performed. They are not required for the actual calculations themselves but are useful to extract additional information from their results, either as consistency checks or to infer derived quantities for later analysis.

template<typename Q>
void check_SE_causality(const SelfEnergy<Q> &selfEnergy)

Function that checks causality of self-energy Im(Sigma^R)<=0, and writes the result into the log file.

Template Parameters:

Q – Template parameter specifying the type of the data.

Parameters:

selfEnergy – Reference to a self-energy that shall be checked.

template<typename Q>
SelfEnergy<Q> check_FDTs_selfenergy(const SelfEnergy<Q> &selfenergy, const double T, const bool verbose)

Function that checks FDTs for a given self-energy.

Template Parameters:

Q – Template parameter specifying the type of the data.

Parameters:

• selfenergy – Reference to a self-energy that shall be checked.

• T – Temperature at which the FDT shall be evaluated

• verbose – If true, the result of the check is written into the log file

Returns:

Self-energy with the Keldysh component evaluated using the FDT. Can then be compared to the input self-energy.

double sum_rule_spectrum(const State<state_datatype> &state)

Function to compute the sum rule for the spectral function, \int d\nu A(\nu) = 1.

Parameters:

state – Reference to an input state whose self-energy shall be used.

Returns:

Result of the integral, which should be 1.

void compute_postprocessed_susceptibilities(const std::string &filename)

Take hdf5 file, iterate through all layers, and compute the susceptibilities from it and save them to the hdf5 file. Postprocessed K1: K1r = Γ0∘Π_r∘Γ0 + Γ0∘Π_r∘Γ∘Π_r∘Γ_0 = Γ0∘Π_r∘(Γ0 + Γ∘Π_r∘Γ_0) This works because K1r+K2r ∈ Γ∘Π_r∘Γ_0 (zero K2’ or K3)

Parameters:

filename – Reference to a filename with the data that shall be processed.

void save_slices_through_fullvertex(const std::string &filename, const int ispin)

Take hdf5 file, iterate through all layers, evaluate the full vertex Γ in the t-channel parametrization for ω_t = 0 in the (ν_t, ν’_t) plane for all Keldysh components a given spin, and write the results back into the file.

Parameters:

• filename – Reference to a filename with the data that shall be processed.

• ispin – Spin component that shall be computed.