Titlebook: Effective Field Theory for Spontaneously Broken Symmetry; Tomáš Brauner Book‘‘‘‘‘‘‘‘ 2024 The Editor(s) (if applicable) and The Author(s)

Nebulous

https://doi.org/10.1007/978-3-540-45284-3 the point of view of background gauge invariance. The last part of the chapter returns to scattering of Nambu–Goldstone bosons. It shows how the presence of redundant symmetries may lead to the enhancement of scattering amplitudes in the soft limit.

幼稚

Spontaneous Symmetry Breakingchapter is devoted to highlighting some subtle features of spontaneous symmetry breaking. These include the properties of the ground state and the tower of low-lying excited states in a finite volume, and the absence of well-defined unitary operators representing broken symmetry in the thermodynamic limit.

粗俗人

Nambu–Goldstone Bosonsndependent Nambu–Goldstone fields. Finally, a counting rule relating the numbers of independent fields and states in the spectrum is established. The chapter concludes with a brief overview of Nambu–Goldstone-like modes, which are also related to symmetry yet lack one or more of the attributes of genuine Nambu–Goldstone bosons.

或者发神韵

Locally Equivalent Symmetries the point of view of background gauge invariance. The last part of the chapter returns to scattering of Nambu–Goldstone bosons. It shows how the presence of redundant symmetries may lead to the enhancement of scattering amplitudes in the soft limit.

我正派

vitreous-humor

Hirsutism

Symmetry and Conservation Lawslatter. In anticipation of the discussion of spontaneous symmetry breaking in the following chapter, the text here emphasizes the difference between implementing symmetry in terms of transformations on the algebra of physical observables, and in terms of unitary mappings on the Hilbert space of states.

definition

CRUC

ds light on the conditions under which a global symmetry can be gauged. The last section of the chapter revisits the spectrum of Nambu–Goldstone bosons. It is shown, among others, that type-A and type-B Nambu–Goldstone bosons have a distinct geometric interpretation, associated with a presymplectic

红肿

https://doi.org/10.1007/978-3-642-41741-2 subject to perturbations breaking the ideal spin symmetry, and the text thus includes an extended discussion of such effects. The last section draws the reader’s attention to some peculiar properties of ferromagnets, which can be largely traced to the topology of the coset space.