Symmetry Breaking in Biharmonic Equations with Weighted Exponential Nonlinearities

nonlinearities and spatial weights of Hénon type. Motivated by the symmetry-breaking phenomena observed in semilinear second-order problems – such as those governed by the Hénon equation – we consider weighted functionals of the form \begin{equation*} F_m(u) = \int_B |x|^α\left( e^{σ|u|^2} - \sum_{k=0}^m \frac{σ^k}{k!} |u|^{2k} \right) dx, \end{equation*} defined on the unit ball $B\subset {\mathbb{R}}^4$, where $m\in {\mathbb{N}}_0$ $\alpha >0$, $\sigma >0$ are suitable parameters. We first establish an Adams-type inequality with weight, characterizing the sharp threshold for the boundedness of $F$ on the unit sphere of the biharmonic Sobolev space. Then, we prove that for large values of the weight exponent $\alpha$, radial symmetry of maximizers is broken. %, i.e., the supremum of the functional is strictly larger when taken over the full space compared to the radial subspace. These results extend classical findings in the second-order setting (e.g., Trudinger–Moser-type functionals and the weighted Hénon equation) to the biharmonic context and offer new insights into the interplay between weights, nonlinearity, and symmetry in higher-order PDEs.