How to write a downside arrow over a letter?

Feb 2013
24
0
Hungary
Greetings,

I would like to put a downside arrow over a letter in LaTeX, how could I do it? I need it for the convective term of the Navier-Stokes equations to mark which velocity the \(\displaystyle \nabla\) acts on.

Thank you,
Zoli
 

romsek

MHF Helper
Nov 2013
6,746
3,037
California
I'm not seeing what a "downside arrow" is. Do you mean an arrow to mark a variable as a vector as in $\vec{v}$ ?
 
Feb 2013
24
0
Hungary
I mean an arrow that points downwards: for example if the arrow in \(\displaystyle \vec{v}\) would be be rotated -90 degrees, that would be OK.
 

romsek

MHF Helper
Nov 2013
6,746
3,037
California
I mean an arrow that points downwards: for example if the arrow in \(\displaystyle \vec{v}\) would be be rotated -90 degrees, that would be OK.
$\overset{\downarrow}v$

how about that?
 
Feb 2013
24
0
Hungary
Yes, I would like that one.