Tricritical and Critical Exponents in Microcanonical Ensemble of Systems with Long-Range Interactions

We explore the tricritical points and the critical lines of both Blume Emery Griffiths and Ising model within long-range interactions in the microcanonical ensemble.For K = Kmtp,the tricritical exponents take the valuesβ = 1/4,1 =γ^-≠γ^+ = 1/2 and 0 =α^-≠α^+ =-1/2,which disagree with classical(mean ffeld) values.When K > Kmtp,the phase transition becomes second order and the critical exponents have classical values except close to the canonical tricritical parameters(Kctp),where the values of the critical expoents become β = 1/2,1 = γ^-≠γ^+= 2and 0 =α^-≠α^+ = 1.