The operator is called the (real phase) metric operator or fundamental symmetry, and may be used to define the Hilbert inner product :

The flashback in Chapter I travels an equal sixteen years in time, creating a fundamental symmetry.

Further they demonstrated the fundamental symmetry of spin 1/2 particles under rotations.

The whole effect was esthetically pleasing, with a fundamental symmetry such as he had previously discerned in well-shaped human bodies.

Violations of this fundamental symmetry can be studied within this general framework.

They aim to find the fundamental symmetries and mathematical equations that describe how our universe works.

Mr. Zee points out that while they believed in the utility of symmetry, they did not use fundamental symmetries to derive new theories.

Therefore the Lorentz group is said to express the fundamental symmetry of many of the known fundamental Laws of Nature.

Iterating operators on simple forms can produce progressively larger polyhedra, maintaining the fundamental symmetry of the seed element.

The following table summarizes some fundamental symmetries and the associated conserved quantity.