We reorganized a room a few years ago and carpet indentions reminded me every day that furniture had been moved. Drove me crazy! I realized there is a simple way to make the carpet pop back up : hot steam from an iron!
Put distilled water in your iron. Allow the iron to heat. Place a thin washcloth over the surface of the carpet. Place the hot iron on the carpet and press the steam button a few times, pushing the iron back and forth. Remove the iron and washcloth, then move the now pliable carpet fibers into place.
You may need to repeat this process one or two more times depending on the carpet and the weight of the item that created the indention.
Let me know if this post helped you!