**Preface to "Chemical Symmetry Breaking"**

Nowadays, it is well recognized that a concept of the nonlinear complexity theory governs a variety of dynamic phenomena observed in all fields of science; the fluctuation in a nonequilibrium state induces a phase transition from a chaotic or dissipative state to another one to trigger symmetry breaking, and eventually, the nonlinear amplification of fluctuation leads to dissymmetric circumstances. A typical example is the birth of the universe by the cosmic inflation followed by the Big Bang starting from a quantum fluctuation, which finally led to the selection of "matter" against "anti-matter" in the universe, according to a violation of the charge conjugation parity (CP) symmetry. Thus, symmetry breaking has been playing a primordial role in physics, chemistry, life science, economics and so on.

This Special Issue focuses on the various chemical and physical phenomena that originate from symmetry breaking occurring upon a thermally or photochemically induced phase transition in the organic condensed phases, such as metastable liquid crystals, crystals, amorphous solids, and colloidal polymer materials under nonequilibrium conditions, including an experimental and theoretical report on the connection of dressed photons with cosmology.

> **Rui Tamura** *Editor*

*Review*
