Side question, what's a good HARDKKKORE sci-fi book that depicts capital ships in spess combat?
In my opinion, the Dread Empire's Fall trilogy by Walter John Williams has the most realistic space combat that I know of. It can be sumarized to capital ships (very nuclear submarine-like) carrying shittons of antimatter missiles and a few fighters. The fighters don't go pew-pew-ing like retards but are used for forward targeting and guidance of groups of already launched missiles. Apart from animatter missiles, there is limited use of beam weaponry for point defense. That's strictly knife-fight range hardware used in the vast majority of situations to defend against incoming missiles that managed to pass through the defending ship's defensive missile screen.
In space combat, I think that everything can be rationalized starting from two budgets: the delta-v (speed variation) bugdet and the delta-T (temperature variation) budget.
delta-v: You can't just senslessly accelerate and decelerate or you'll end up stranded. If you say "..bbbbut nuclear power", the problem with that is that a nuclear reactor can be used to generate electricity, but unlike in the case of a nuclear sub, which can use that electricity to drive a propeller shaft which moves the sub by creating thrust based on the fluid in which the sub operates, in space you are surrounded by void, so the only way to generate thrust is through using an engine that expells reaction mass. That means that you would need to carry that reaction mass onboard and that shit takes space and adds mass to the whole ensemble. The alternative to that is to use a ion drive, which still needs fuel, only much less of it, but offers very little thrust, so it wouldn't make for a great engine for military vessels which would want as much maneuvrability as possible
delta-T: As it has already been discussed, thermal management in space is a bitch because dissipating heat in space is a bitch. That means that you don't want weapon systems that senslessly increase the temperature of your vessels, otherwise you'll roast yourselves alive without the enemy having to do shit but dodge a few of your shots. That means that lasers are out the door (without mentioning the whole beam coherence issue and thermal management issues, there are targetting issues and the fact that, unlike what you see in movies, you would need to keep that beam on the same spot of the target for a while in order to get a result, which is quite difficult at the ranges involved in space and taking into account the fact that the enemy will be maneuvering like crazy in order not to allow you to do that), mass drivers are out the door (because accelerating that slug using a rail gun or coil gun also generates massive amounts of heat. The ship may become uninhabitable after a dozen shots, if not less). That leaves missiles. Missiles can be free to fire (from a delta-T standpoint) and they have the added benefit of being able to maneuver in order to home in on the target. Put a nuclear (if you don't have antimatter) warhead on them and watch the fireworks. The thing with nuclear blasts is that even without the shockwave (because, as Hellraiser was saying previously, you can't have a shockwave without air), you still have thermal and, more importantly, electromagnetic radiation which can fuck up your day even without a direct hit.
So, at this point, the big arsenal-ship-like capitals ships combined with fast and small human-crewed ships for better intel, targeting and guidance of the missiles plus a LOT of missiles seems to me like the best combination. The missiles are, of course, completely automatic, the recce ships can have even just on human crew member and the arsenal ships can have bigger, but still relatively small crews by using automation as much as possible. From this point on, you can start improving on the various parts of the system. For example, you can look into quantum entanglement communication devices between the arsenal ships and the recce ships, so that you eliminate the delays inherent the ranges involved in space warfare. You can improve the missiles so that they work like loitering munitions. This way, you can fire them ahead of time and just let them out there like a minefield that keeps an eye out for intruders. If someone tries to approach, they first communicate that to their controlling arsenal ship or recce ship and then they swarm the intruder or hold back depending on their programming and/or newly received commands.
The concept of stealth is ridiculous in space. Even if you can manage some EM spectrum stealth, you can't get thermal stealth. The concept of cryogenically lowering the temperature of the outer shell of the ship is ridiculous because cryogenics need massive amounts of energy which requires significant power generation capabiliies and we end back to the fact that you would turn the inside of the ship in a steamer very quickly by doing that.
Also, the concept of formation combat is retarded. One nuclear (antimatter) missile can take out a whole chunk of a fleet that is grouped in a tight formation. You would have better chances by using at least a loose formation. Better, there should not be any discernable formation a all. You should spread out your fleet and coordinate your attack so that your fleet hits the enemy simultaneously from multiple sides (and please, please try to remember that space is 3D, so think in 3 dimensions. This isn't Gettysburg or Verdun).
GOTY 2012 it is then...
