Code-equations/Gravitational-Potential-including-indirect-terms.md

-[[_TOC_]]
+
 
 The gravitational potential entering in the source terms of the Navier-Stokes equations is the sum of multiple terms:
-## The potential from the central massive body (primary of mass $`M_*`$):
+## The potential from the central massive body
+Considering a primary of mass $`M_*`$:
 
    $`\Phi_*=-{{ G M_*} \over {r}}`$
-## The potential form the planets of mass $m_p$. 
-   Below we consider the case of one single planet, easily extended to multiple planets.
+## The potential form the planets
+   Below we consider the case of one single planet  of mass $m_p$ (it is easily extended to multiple planets).
 - In the 3 Dimensional case 
 we use  a cubic-potential of the form:
 
@@ -57,7 +58,10 @@ To select this choice for a simulation in the config file:
 ```
 
 ## The indirect terms 
-This term in the potential accounts for the acceleration of the primary 
+Two terms in the potential accounts for the acceleration of the primary they come  from the acceleration  due respectively to the planet(s) and to the disk:
+
+$`\tilde \Phi_p = {{ G m_p} \over {r_p^3}}(r_p\codot r)`$
+