Heavy handed quest for fixed points in multiple coupling scalar theories in the ε expansion
Hugh Osborn, Andreas Stergiou
Abstract
A bstract The tensorial equations for non trivial fully interacting fixed points at lowest order in the ε expansion in 4 − ε and 3 − ε dimensions are analysed for N -component fields and corresponding multi-index couplings λ which are symmetric tensors with four or six indices. Both analytic and numerical methods are used. For N = 5 , 6 , 7 in the four-index case large numbers of irrational fixed points are found numerically where ‖ λ ‖ 2 is close to the bound found by Rychkov and Stergiou [1]. No solutions, other than those already known, are found which saturate the bound. These examples in general do not have unique quadratic invariants in the fields. For N ⩾ 6 the stability matrix in the full space of couplings always has negative eigenvalues. In the six index case the numerical search generates a very large number of solutions for N = 5.