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Tolerant indirect reciprocity can boost social welfare through solidarity with unconditional cooperators in private monitoring

, Saitama, 337-8570, JapanYutaka Nakai AuthorsSearch for Isamu Okada in:Nature Research journals • PubMed • Google Scholar Search for Tatsuya Sasaki in:Nature Research journals • PubMed • Google Scholar ... simulation. All authors wrote the paper. Competing Interests The authors declare that they have no competing interests. Corresponding author Correspondence to Isamu Okada. Electronic supplementary

A norm knockout method on indirect reciprocity to reveal indispensable norms

of Mathematics, Vienna, 1090, AustriaTatsuya Sasaki AuthorsSearch for Hitoshi Yamamoto in:Nature Research journals • PubMed • Google ScholarSearch for Isamu Okada in:Nature Research journals • PubMed

The Effect of Incentives and Meta-incentives on the Evolution of Cooperation

Although positive incentives for cooperators and/or negative incentives for free-riders in social dilemmas play an important role in maintaining cooperation, there is still the outstanding issue of who should pay the cost of incentives. The second-order free-rider problem, in which players who do not provide the incentives dominate in a game, is a well-known academic challenge...

Probabilistic participation in public goods games

Voluntary participation in public goods games (PGGs) has turned out to be a simple but effective mechanism for promoting cooperation under full anonymity. Voluntary participation allows individuals to adopt a risk-aversion strategy, termed loner. A loner refuses to participate in unpromising public enterprises and instead relies on a small but fixed pay-off. This system leads to...

Mean-Field Theory of Antiferromagnetic Spin Hamiltonian with Four Spin Interactions for bcc Lattice

An antiferromagnetic spin Hamiltonian with four spin interactions for bcc lattice is investigated on the assumption of four sublattices within the mean-field approximation. Phase diagrams are calculated in the parameter space for zero field. They possess a weak ferromagnetic phase. The effects of the magnetic field on the model are discussed in detail. The susceptibility of the...

Singlet Ground State of the Localized d-Electrons Coupled with Conduction Electrons in Metals

The theory of the singlet ground state for the s-d exchange model is extended to the core of d-electrons with orbital degeneracy. The effective s-d Hamiltonian is derived from the extended Anderson Hamiltonian by the Schrieffer-Wolff canonical transformation. On the basis of the effective Hamiltonian, the ground-state wave function and the ground-state energy are calculated. The...