red-carpet vs red carpet

red-carpet is not a noun while red carpet is a noun.

Word	Noun	Adjective	Verb	Adverb
red-carpet	No	Yes	No	No
red carpet	Yes	Yes	No	No

As adjectives, red-carpet and red carpet are synonyms defined as:

red-carpet (noun)	red carpet (noun)
	a strip of red carpeting laid down for dignitaries to walk on

red-carpet (adjective)	red carpet (adjective)
special treatment or hospitality	special treatment or hospitality