is the use of consevation laws compulsory in relativistic dinamics?
this is an ill-posed question, your works need to comply with conservation laws at all times (relativity or not)
i think the question is well-posed. the derivation can be accomplished without using the conservation laws and to show after that the derived relativistic momentum and mass comply with them.
Then why do you ask? Prove it.
Even if you follow these steps (you seem to already have a paper "up your sleeve") it still means that you are employing the conservation laws (after the fact instead of before). So is this another set-up for another one of your self-promoting links to another one of your archived papers?
Well of course you know what you mean!
Let's look at the question again, shall we?
I think this question turns on what you mean by "use".
When you say "use" are you referring to the explicit invocation of the conservation laws when doing calculations in relativistic dynamics? Or are you referring to the use of statements which are not explicit statements of the conservation laws, but from which those laws follow deductively? It sounds from your responses like you mean the latter, in which case I would agree. Newtonian dynamics is equivalent to the conservation laws, and the latter needn't be referred to outright when doing dynamical calculations.
Separate names with a comma.