Hence, the only potentials that can produce stable closed non-circular orbits are the inverse-square force law (β = 1) and the radial harmonic-oscillator potential (β = 2).
hˈɛns, ðɪ ˈoʊnli pətˈɛnʃəlz ðæt kæn pɹədˈuːs stˈeɪbəl klˈoʊzd nˈɑːnsˈɜːkjʊlɚɹ ˈɔːɹbɪts ɑːɹ ðɪ ɪnvˈɜːsskwˈɛɹ fˈoːɹs lˈɔː bˈeɪɾə ˈiːkwəlz wˈʌn ænd ðə ɹˈeɪdɪəl hɑːɹmˈɑːnɪkˈɑːsɪlˌeɪɾɚ pətˈɛnʃəl bˈeɪɾə ˈiːkwəlz tˈuː.