Maintainers for fftw3 are Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>.
You may want to refer to the following packages that are part of the same source: libfftw3-3, libfftw3-bin, libfftw3-dev, libfftw3-doc, libfftw3-double3, libfftw3-long3, libfftw3-mpi-dev, libfftw3-mpi3, libfftw3-quad3, libfftw3-single3.
You might like to refer to the fftw3 package page, to the Package Tracking System, or to the source package src:fftw3's bug page.
If you find a bug not listed here, please report it.