DOI: 10.1140/epjc/s10052-026-16386-5 ISSN: 1434-6052

Bianchi IX dynamics with a phantom field

Adel Awad, Dmitry Chirkov, Alexey Golovnev, Alexey Toporensky

Abstract

We consider Bianchi IX dynamics of a Universe filled with a massless phantom field. Such an exotic matter source enables regimes impossible in vacuum or with a standard scalar field. In particular, two Kasner indices of BKL oscillations can be simultaneously negative, and the absolute value of a negative index can be large. We describe the consequences of these features and explain the nature of volume oscillations recently discovered in such a system by numerical methods.