= Field crossover exponent
{title2=$\Delta=\beta\delta=\beta+\gamma$}
The <field crossover exponent> describes the field scale $h\sim|t|^\Delta$ at which the zero-field critical regime changes. In the two-variable <scaling hypothesis for critical phenomena>, its value is the ratio $y_h/y_t$ of magnetic and thermal <scaling dimensions>. It is distinct from either $y_h$ or the <scaling dimension> of the <order parameter>. The <Widom scaling relation> and differentiation of the homogeneous <free-energy density> give the displayed identities when ordinary scaling applies.
Back to article page
