Relativistic qm Definition and 15 Threads

In non-relativity then there is QM, but in relativistic regime then there is QFT. Then what is useful role of Relativistics QM nowaday, or it is only has a historical meaning?Does non-existance wave function in relativistic regime make RQM meaningless?

I loved Modern Quantum Mechanics by Sakurai, where Quantum Mechanics is presented and worked out. Now I would like to proceed further, and learn about Relativistic Quantum Mechanics and Quantum Field Theory. I started by reading Sakurai's Advanced Quantum Mechanics, but later I found that the...

When constructing a relativistic quantum mechanical equation, namely Dirac equation, what would happen if we choose the Hamiltonian so that it's not linear in the momentum operator and the rest energy? You could say, why don't try it yourself and see what happens? That's because my knowledge is...

I was reading that one of the successes of the Dirac equation was that it was able to account for the fine structure of some of the differences in the spectrum of the hydrogen atom. But the Dirac equation is about subatomic particles moving at relativistic velocities. But an electron around the...

I've read that one of the primary motivations for the need for QFT is that quantum mechanics cannot account for particle creation/annihilation, however special relativity "predicts" that such phenomena are possible (clearly they have been observed experimentally, but I'm going for a heuristic...

If a photon does not experience time, how can it change? Without change, how can it have frequency?

SO(3) is subgroup of Poicare group.Does Relativistic Quantum Mechanics obey rotational symmetry.If it is,why we do not still keep the non-relativistic concept of angular momentum(orbit angular momentum plus spin) for relativistic concept of angular momentum,but we instead replace the concept by...

Problem statement, equations, and work done: A particle called a Kaon is moving at 0.8c through a detector when it decays into two pions. Kaon particle: mass = 493.7 MeV/c^2 Pion+: mass = 139.6 MeV/c^2 Pion0: mass = 135.0 MeV/c^2 1) Apply conservation of momentum/energy to determine the...

In non-relativistic QM, the probability postulate works very well in position and momentum space. But, I have read that in relativistic QM (Dirac or QFT), the probability postulate in position space does not work because the corresponding probability density function is not Lorentz covariant...

I'd liked to know whether the postulates of standard QM are still valid in Relativistic QM By postulates I mean what is ussually stated in texbooks as follows 1)Physical states are determined by a vector in sate space E 2)A measurable physical quantity A is described by an observable A acting...

Dear users, I wonder if there is anybody who can give me a hint on how to handle the following situation: In the 2+1 dimensional Klein-Gordon equation with coordinates (t,x,y), I use as initial condition for \Psi(x,0) a spherically symmetric Gaussian. The relativistic dispersion relation...

I've been wondering about relativistic quantum mechanics. Elsewhere I'm addressing some comments about this branch of physics but I have never studied it. Is the 4-momentum 4-vector defined in the same way in relativsitic QM or is there a difference? I'm wondering if the time component of...

Hi, I'm a bit befuddled about something my lecturer wrote: S^{\dagger}\sigma_{\alpha}R_{{\alpha}\beta}B_{\beta}S=R_{{\alpha}\beta}B_{\beta}S^{\dagger}\sigma_{\alpha}S R is a 3x3 rotation matrix which transforms the magnetic field B between frames, sigma_alpha are the pauli...

http://arxiv.org/abs/gr-qc/0508104 Towards a fully consistent relativistic quantum mechanics and a change of perspective on quantum gravity 17 pages, submitted to CQG "This paper can be seen as an exercise in how to adapt quantum mechanics from a strict relativistic perspective while being...

Hi there, I have a problem that I could really do with a little help on. I have a spin 1/2 particle in which the dirac eqtn reads: ( i {d} - \gamma V(x) - m ) \Phi = 0 (I am new to latex - the d is SLASHED and the gamma is GAMMA5 ) In a potential V(x,t) = 0 for...