### Abstract

We discuss fermion grading symmetry for quasi-local systems with graded commutation relations. We introduce a criterion of spontaneously symmetry breaking (SSB) for general quasi-local systems. It is formulated based on the idea that each pair of distinct phases (appeared in spontaneous symmetry breaking) should be disjoint not only for the total system but also for every complementary outside system of a local region specified by the given quasi-local structure. Under a completely model independent setting, we show the absence of SSB for fermion grading symmetry in the above sense. We obtain some structural results for equilibrium states of lattice systems. If there would exist an even KMS state for some even dynamics that is decomposed into noneven KMS states, then those noneven states inevitably violate our local thermal stability condition.

Original language | English |
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Pages (from-to) | 411-426 |

Number of pages | 16 |

Journal | Communications in Mathematical Physics |

Volume | 264 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2006 Jun |

Externally published | Yes |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Statistical and Nonlinear Physics
- Mathematical Physics

### Cite this

*Communications in Mathematical Physics*,

*264*(2), 411-426. https://doi.org/10.1007/s00220-006-1550-7

**On fermion grading symmetry for quasi-local systems.** / Moriya, Hajime.

Research output: Contribution to journal › Article

*Communications in Mathematical Physics*, vol. 264, no. 2, pp. 411-426. https://doi.org/10.1007/s00220-006-1550-7

}

TY - JOUR

T1 - On fermion grading symmetry for quasi-local systems

AU - Moriya, Hajime

PY - 2006/6

Y1 - 2006/6

N2 - We discuss fermion grading symmetry for quasi-local systems with graded commutation relations. We introduce a criterion of spontaneously symmetry breaking (SSB) for general quasi-local systems. It is formulated based on the idea that each pair of distinct phases (appeared in spontaneous symmetry breaking) should be disjoint not only for the total system but also for every complementary outside system of a local region specified by the given quasi-local structure. Under a completely model independent setting, we show the absence of SSB for fermion grading symmetry in the above sense. We obtain some structural results for equilibrium states of lattice systems. If there would exist an even KMS state for some even dynamics that is decomposed into noneven KMS states, then those noneven states inevitably violate our local thermal stability condition.

AB - We discuss fermion grading symmetry for quasi-local systems with graded commutation relations. We introduce a criterion of spontaneously symmetry breaking (SSB) for general quasi-local systems. It is formulated based on the idea that each pair of distinct phases (appeared in spontaneous symmetry breaking) should be disjoint not only for the total system but also for every complementary outside system of a local region specified by the given quasi-local structure. Under a completely model independent setting, we show the absence of SSB for fermion grading symmetry in the above sense. We obtain some structural results for equilibrium states of lattice systems. If there would exist an even KMS state for some even dynamics that is decomposed into noneven KMS states, then those noneven states inevitably violate our local thermal stability condition.

UR - http://www.scopus.com/inward/record.url?scp=33645961311&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645961311&partnerID=8YFLogxK

U2 - 10.1007/s00220-006-1550-7

DO - 10.1007/s00220-006-1550-7

M3 - Article

AN - SCOPUS:33645961311

VL - 264

SP - 411

EP - 426

JO - Communications in Mathematical Physics

JF - Communications in Mathematical Physics

SN - 0010-3616

IS - 2

ER -