Can you provide a bit more information and possible a photo taken with flash? Perhaps a floor plan of the kitchen layout you are proposing and how it relates to the arch?

The photo was taken from the living room. The archway is
from the living room down two stairs to the kitchen. I am looking for ideas for doors or shutters. It is 79 inches high and. 66 inches wide. The living space is very big so needs some kind of partition to keep the heat in. Thanks for your help.

Given the presence of stairs, installing doors truly concerns me with regards to people safety. The doors will have people looking up and could easily trip down the stairs unexpectedly. Obscurity is probably your objective here so no doors does not help but if you had a muralist paint around the arch that could be a really nice feature.