title: Tricritical points in biaxial liquid crystal phases.
abstract: We further pursue the analysis of a mean-field model recently proposed by Sonnet [Phys. Rev. E 67, 061701 (2003)] to describe nematic biaxial phases. This model, which is based on a simplified version of Straley's pair potential, is characterized by the prediction of a tricritical point along the transition line between uniaxial and biaxial phases. We show that the same model predicts another tricritical point, but along the line of the direct isotropic-to-biaxial transition. Our prediction is quantitative, as it stems from an analytical criterion for tricriticality.
authors.affiliation: Scuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. g.dematteis@sns.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Matteis
authors.forename: Epifanio G
authors.initials: EG
authors.lastname: Virga