Can i travel to Brazil if my greencard expired?

I renewed it a month ago, but didn't receive it yet. is there any permission i neeed to get so i can travel without my green card from the us to brazil? thank you
I am just staying for two weeks because i go to school here...

Yeah, but i dont think they'll let u back in.

nooooooo. ten thousand times nooooooo.
you can't get to senior without passing through junior right?
be patient, wait for your new green card and then travel... if you leave like that you are running chances of getting refused back into the country as soon as you get to the immigration check point in the airport.

You can go out of the country but you wont allowed back in.

Check with USCIS, you may be able to get travel authorization. Although they don't exactly move fast. If you do not get that then wait for your new card.

you can travel there but you'll have problems getting back in. one way for you is go to the nearest USCIS office near you and ask for a temporary one. if you explain the reason why, they might grant you permission to go and come back. bring the receipt of your green card renewal to the appointment though.

www.infopass.com for appointment.

If you have an emergency situation, fill out Form I-551 and take your green card approval notice to your latest USCIS field office. They can put a stamp in your passport that will allow you to travel.

There is a fee for this, but I'm not sure how much it is.

wait till you get the card before you leave. or you will most likely NOT be allowed back in.

what do you mean going to school? if you are away from UAS for more than 6 months you lose your green card - unless you have applied for permission to be away for a longer time period.