English: As T-symmetry produces energy and mass inversion (when the T operator is chosen linear and unitary as in the Janus model), it refers to the negative sector. There are then four species:

• Positive mass matter: our common matter, what we are made of. Prevailed in our sector. • Positive mass antimatter: C-symmetry with respect to our matter. It may be called "Dirac's antimatter". It is the antimatter created in lab. It has positive energy and mass, and falls down in the Earth gravitational field. • Negative mass matter: CPT-symmetry with respect to our matter. The "twin matter", "shadow matter" or "matter of the negative sector".

• Negative mass antimatter: C×CPT = PT-symmetry with respect to our matter. It may be called "Feynman's antimatter". It is the "missing" cosmological antimatter, the species that prevailed in the negative sector due to an opposite CP violation with respect to the positive sector, according to the Sakharov conditions. Since it has negative energy and mass, it "falls up" in the Earth gravitational field.