I suppose it depends on what kind of technology you're going to use. I probably have a different image in mind to you when we're discussing carriers. To mind my the carrier is mainly a platform for the strike craft. It will have a fair ammount of defenses, but its offensive power is it's strike groups, hence not much in the way of big guns itself. Without the carrier to provide repair and refit, the strike craft are a one shot weapon, and if something gets in range to damage the carriers themselves, that reduces the overall effectiveness of the strike groups .. loss of supplies, crew, and so forth.
Have you read any of the Honor Harrington novels? Plenty of space warfare there, with ships ranging from not quite fighters up to superdreadnoughts, and the LACs (Light Attack Craft .. the not quite fighters) being relatively useless for much of the series, with the wall of battle being dreadnoughts and superdreadnoughts. Battleships are useful to deter cruiser raiding fleets, since the lighter craft can generally outrun the heavier, it makes cruisers and battlecruisers well suited to deep raids on the enemy infrastructure and commerce.