We consider rates of separation between two particles greater than c (which is not in contradiction with special relativity) in understanding some conflict between special relativity and quantum mechanics found by moving observers of correlated EPR pairs of photons. The photon frequencies observed in the moving frame have opposite shifts than those found when the detectors are fixed in that frame. By observing from two different frames the arrival of a photon from an EPR pair to a given detector, it is illustrated how the measurement of the simultaneous arrival of the other photon of the EPR pair in one frame disturbs the measurement in the other frame.

Consideramos velocidades de separación entre dos partículas mayores que c (lo que no está en contradicción con la relatividad especial) en la búsqueda de la comprensión del conflicto entre la relatividad especial y la mecánica cuántica, encontrado por observadores móviles de pares correlacionados de fotones EPR en movimiento. Las frecuencias de los fotones observadas en el marco de referencia móvil tiene desplazamiento opuesto al que se encuentra cuando los detectores están fijos en tal marco. Mediante la observación, desde dos marcos diferentes, del arribo de uno de los fotones de un par EPR a un detector dado, se ilustra cómo la medición del arribo simultáneo del fotón contraparte en uno de los marcos, perturba la medición del arribo simultáneo de dicho fotón en cualquier otro marco.

We discuss the occurrence of Bose-Einstein condensation in systems of noninteracting charged particles in three and one dimensions and in presence of an external magnetic field. In the one dimensional, as well as in the magnetic field cases, although not a critical temperature, a characteristic temperature can be found, corresponding to the case in which the ground state density becomes a macroscopic fraction of the total density. The case of relativistic charged scalar and vector particles is studied. The results give support to the existence of superconductivity in extremely strong magnetic fields, and lead to the prediction of superconductive-ferromagnetic behavior in the vector field case, which might be of interest in condensed matter as well as in cosmology. Some features of the magnetization in the early universe are conjectured.