# Thread: How to write a downside arrow over a letter?

1. ## How to write a downside arrow over a letter?

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 $\nabla$ acts on.

Thank you,
Zoli

2. ## Re: How to write a downside arrow over a letter?

I'm not seeing what a "downside arrow" is. Do you mean an arrow to mark a variable as a vector as in $\vec{v}$ ?

3. ## Re: How to write a downside arrow over a letter?

I mean an arrow that points downwards: for example if the arrow in $\vec{v}$ would be be rotated -90 degrees, that would be OK.

4. ## Re: How to write a downside arrow over a letter?

Originally Posted by Zoli
I mean an arrow that points downwards: for example if the arrow in $\vec{v}$ would be be rotated -90 degrees, that would be OK.
$\overset{\downarrow}v$

5. ## Re: How to write a downside arrow over a letter?

Yes, I would like that one.

6. ## Re: How to write a downside arrow over a letter?

Originally Posted by Zoli
Yes, I would like that one.
\overset{\downarrow}{v}

$\overset{\downarrow}{v}$

7. ## Re: How to write a downside arrow over a letter?

You might find this site to be of help.

-Dan

8. ## Re: How to write a downside arrow over a letter?

Thank you very much!

9. ## Re: How to write a downside arrow over a letter?

Originally Posted by topsquark
You might find this site to be of help.

-Dan
Wow, amazing site.