Nambu-Goldstone bosons with fractional-power dispersion relations

Cosmology with ultralight pseudo Nambu-Goldstone bosons.

We explore the cosmological implications of an ultra-light pseudo-Nambu-Goldstone boson. With global spontaneous symmetry breaking scale f ' 10 18 GeV and explicit breaking scale comparable to MSW neutrino masses, M 10 3 eV, such a eld, which acquires a mass m M 2 =f H 0 , would have become dynamical at recent epochs and currently dominate the energy density of the universe. The eld acts as an ...

Production by Nambu Goldstone Bosons with Application to Inflation Rehea

A semiclassical calculation of particle production by a scalar field in a potential is performed. We focus on the particular case of production of fermions by a NambuGoldstone boson θ. We have derived a (non)local equation of motion for the θ-field with the backreaction of the produced particles taken into account. The equation is solved in some special cases, namely for purely Nambu-Goldstone ...

Lightest scalars as chiral partners of the Nambu–Goldstone bosons

We review the spectrum of lightest scalar resonances recently determined using dispersion techniques. The conceptual difference between the pole mass and the bare mass (or the line–shape mass) is stressed. The nature of the lightest scalars are discussed and we argue, without relying on any model details, that the σ(500), κ(700), a0(980) and f0(980) may be understood as chiral partners of the N...

Multicritical Symmetry Breaking and Naturalness of Slow Nambu-Goldstone Bosons

Fluctuation-induced Nambu-Goldstone bosons in a Higgs-Josephson model

We present a new mechanism of fluctuation-induced Nambu-Goldstone bosons in a scalar field theory of Higgs-Josephson systems. We consider a simple scalar field model with U(1) rotational symmetry. When there is an interaction which violates the rotational symmetry, the Nambu-Goldstone bosons become massive and massless bosons are concealed. We present a model where the massive boson becomes a m...