We prove some inf–sup and sup–inf formulae for the so–called effective multiplication factor arising in the study of reactor analysis. We treat in a same formalism the transport equation and the energy–dependent diffusion equation.

In a four dimensional theory of gravity with lagrangian quadratic in curvature and torsion, we compute the effective action for metrics of the form gμν = ρ δμν , with ρ constant. Using standard field-theoretic methods we find that one loop quantum effects produce a nontrivial effective potential for ρ. We explain this unexpected result by showing how our regularization procedure differs from th...

appreciated by most men. In the business world, risk, when adroitly judged, can lead to significant rewards. By contrast, most men tend to be somewhat risk averse, not only financially, but also more importantly in terms of approaching their health. Attitudes between the sexes vary, as does their willingness to seek medical help and advice. Women tend to seek help earlier and are much more like...