# Copyright (c) 2022-2023 Simons Foundation
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You may obtain a copy of the License at
# https:#www.gnu.org/licenses/gpl-3.0.txt
#
# Authors: Michel Ferrero, Dominik Kiese, Nils Wentzell
import math
[docs]
class MatsubaraFreq:
r""" TRIQS Matsubara frequency
Castable to complex, arithmetic operations implemented by cast
Parameters
----------
n: int
The Matsubara index
beta: double
The inverse temperature
statistic: str
The particle statistic, 'Fermion' or 'Boson'
Attributes
----------
n: int
The Matsubara index
beta: double
The inverse temperature
statistic: str
The particle statistic, 'Fermion' or 'Boson'
"""
[docs]
def __init__(self, n, beta, statistic="Fermion"):
self.n = n
self.beta = beta
self.statistic = statistic
self.is_fermion = (True if self.statistic == "Fermion" else False)
def __complex__(self):
return 1j * (2*self.n + self.is_fermion) * math.pi / self.beta
@property
def imag(self):
return complex(self).imag
@property
def real(self):
return 0.0
@property
def value(self):
return complex(self)
def __abs__(self):
return abs(complex(self))
def __add__(self, other):
if isinstance(other, MatsubaraFreq):
if not self.beta == other.beta:
raise RuntimeError(f"Values of beta do not match: self.beta={self.beta} other.beta={other.beta}")
is_fermion = self.is_fermion ^ other.is_fermion
statistic = "Fermion" if is_fermion else "Boson"
return MatsubaraFreq(self.n + other.n + (self.is_fermion and other.is_fermion), self.beta, statistic)
else:
return complex(self) + other
def __neg__(self):
return MatsubaraFreq(-self.n - self.is_fermion, self.beta, self.statistic)
def __radd__(self, other):
return self.__add__(other)
def __sub__(self, other):
return self.__add__(other.__neg__())
def __rsub__(self, other):
neg = self.__neg__()
return neg.__add__(other)
def __mul__(self, other):
return complex(self) * other
def __rmul__(self, other):
return other * complex(self)
def __truediv__(self, other):
return complex(self) / other
def __rtruediv__(self, other):
return other / complex(self)
def __pow__(self, other):
return complex(self)**other
def __str__(self):
return f"MatsubaraFreq(n: {self.n}, beta: {self.beta}, statistic: {self.statistic})"