Adding return typing for Mc_m1_to_m2, and only return the real root i…

…n that function

src/jimgw/single_event/transforms.py

@@ -89,13 +89,13 @@ def __init__(
         m_1_turning_point_2 = Mc_q_to_m1_m2(self.M_c_max, self.q_max)[0]
 
         def m2_range_regime_1(m_1: Float):
-            lower_bound = Mc_m1_to_m2(self.M_c_min, m_1)[0].real
+            lower_bound = Mc_m1_to_m2(self.M_c_min, m_1)
             upper_bound = self.q_max * m_1
             return [lower_bound, upper_bound]
 
         def m2_range_regime_3(m_1: Float):
             lower_bound = self.q_min * m_1
-            upper_bound = Mc_m1_to_m2(self.M_c_max, m_1)[0].real
+            upper_bound = Mc_m1_to_m2(self.M_c_max, m_1)
             return [lower_bound, upper_bound]
 
         if m_1_turning_point_2 >= m_1_turning_point_1:
@@ -112,8 +112,8 @@ def m2_range_regime_2(m_1: Float):
                 self.regime_2_mass_ratio,
                 lambda x: [self.q_min * x, self.q_max * x],
                 lambda x: [
-                    Mc_m1_to_m2(self.M_c_min, x)[0].real,
-                    Mc_m1_to_m2(self.M_c_max, x)[0].real,
+                    Mc_m1_to_m2(self.M_c_min, x),
+                    Mc_m1_to_m2(self.M_c_max, x),
                 ],
                 m_1,
             )

src/jimgw/single_event/utils.py

@@ -38,7 +38,7 @@ def inner_product(
     return 4.0 * jnp.real(trapezoid(integrand, dx=df))
 
 
-def Mc_m1_to_m2(Mc: Float, m1: Float):
+def Mc_m1_to_m2(Mc: Float, m1: Float) -> Float:
 
     a = jnp.power(m1, 3.0)
     b = 0.0
@@ -57,10 +57,8 @@ def Mc_m1_to_m2(Mc: Float, m1: Float):
     U = jnp.cbrt(T)
 
     x1 = (S + U) - (b / (3.0 * a))
-    x2 = -(S + U) / 2 - (b / (3.0 * a)) + (S - U) * jnp.sqrt(3.0) * 0.5j
-    x3 = -(S + U) / 2 - (b / (3.0 * a)) - (S - U) * jnp.sqrt(3.0) * 0.5j
 
-    return jnp.array([x1, x2, x3])
+    return x1.real
 
 
 def m1_m2_to_M_q(m1: Float, m2: Float):