Is it permissible for me to take back my wife after I divorced her three times, and the judge confirmed my divorce to her, and made me understand that she is irrevocably divorced from me with a major separation (baynunah kubra)?

As long as you have divorced your wife with three pronouncements of divorce, she has become irrevocably separated from you; you do not have the right to take her back unless she marries another husband – a marriage of desire, not a marriage of analysis (tahlil) – and the new husband consummates the marriage with her, then divorces her or dies, and her waiting period (iddah) from him ends.