Is the construction a typical wood framing + sheetrock?

If the ceiling height is higher than 8', you could consider putting in cove lighting.

It is not necessary to install a false ceiling.

David, the slab is concrete and the ceiling height is 10 feet. We like open spaces more and which is why we want ceiling lights fitted to the slab and not put a second layer of recessed ceiling. Our electrical engineer told us that if we put ceiling lights directly into the slab they may show on the outside for about 2-3 inches and we are not sure how it would look. Most of the ceiling lights installation we have seen are with drop ceiling.

If it is possible to dig a small trench to fit in the necessary wiring and junction boxes, you could utilize a low profile (flush mount) disc light available under Halo, Commercial Electric, Sylvania, ... The light is < 1" in height.

commercial electric

Cove lighting may be easier to implement as there is no trenching required as the lighting is hidden above a ledge high on the wall.