# ill-defined

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**BRST quantization**— In theoretical physics, BRST quantization (where the BRST refers to Becchi, Rouet, Stora and Tyutin) is a relatively rigorous mathematical approach to quantizing a field theory with a gauge symmetry. Quantization rules in earlier QFT frameworks… …72

**Trace operator**— In mathematics, the concept of trace operator plays an important role in studying the existence and uniqueness of solutions to boundary value problems, that is, to partial differential equations with prescribed boundary conditions. The trace… …73

**Greece, history of**— ▪ Byzantine to modern Introduction history of the area from the Byzantine (Byzantine Empire) period, beginning about AD 300, to the present. For earlier periods, see Aegean civilizations; ancient Greek civilization; and Hellenistic Age.… …74

**Milecastle 9**— Coordinates: 54°59′27″N 1°43′20″W / 54.990701°N 1.722327°W / 54.990701; 1.722327 …75

**Model of Hierarchical Complexity**— The model of hierarchical complexity is a framework for scoring how complex a behavior is. It quantifies the order of hierarchical complexity of a task based on mathematical principles of how the information is organized and of information… …76

**Orbital magnetization**— Orbital magnetization, , refers to the magnetization induced by orbital motion of charged particles, usually electrons, in solids. The term orbital distinguishes it from the contribution of spin degrees of freedom, , to the total magnetization. A …77

**Puhua**— Not to be confused with Pu Hua. Puhua Zhenzhou Pǔhuà (鎮州普化) A modern depiction of the folkloric Puhua ringing his hand bell, by artist John Singer c. 2001. R …78

**Ockham’s world and future**— Arthur Gibson PHILOSOPHICAL BIOGRAPHY Ockham was born in about 1285, certainly before 1290, probably in the village of Ockham, Surrey, near London. If his epitaph is accurate, he died on 10 April 1347. Yet Conrad of Megenberg, when writing to… …79

**Subpoena duces tecum**— A subpoena duces tecum (or subpoena for production of evidence) is a court summons ordering a named party to appear before the court and produce documents or other tangible evidence for use at a hearing or trial. The summons is known by various… …80

**History of the Balkans**— The Balkans is an area of southeastern Europe situated at a major crossroads between mainland Europe and the Near East. The distinct identity and fragmentation of the Balkans owes much to its common and often violent history and to its very… …