regroup_spin_segment.hpp

// Copyright (c) 2022--present, The Simons Foundation
// Copyright (c) 2022--present, Max Planck Institute for Polymer Research, Mainz, Germany
// This file is part of TRIQS/ctseg and is licensed under the terms of GPLv3 or later.
// SPDX-License-Identifier: GPL-3.0-or-later
// See LICENSE in the root of this distribution for details.
 
#pragma once
#include "../work_data.hpp"
#include "../configuration.hpp"
#include "../invariants.hpp"
 
namespace triqs_ctseg::moves {
 
  class regroup_spin_segment {
    work_data_t &wdata;
    configuration_t &config;
    triqs::mc_tools::random_generator &rng;
 
    // Internal data
    long idx_c_up, idx_cdag_dn, idx_c_dn, idx_cdag_up;
    tau_t tau_up, tau_dn;
    double ln_trace_ratio, prop_ratio, det_sign;
    std::tuple<long, long, tau_t, bool> propose(int color);
 
    public:
    regroup_spin_segment(work_data_t &data_, configuration_t &config_, triqs::mc_tools::random_generator &rng_)
       : wdata(data_), config(config_), rng(rng_) {}
 
    // ------------------
    double attempt();
    double accept();
    void reject();
  };
 
} // namespace triqs_ctseg::moves