No-Signaling Property of the Single-Qudit-State Tomogram

We review the tomographic approach to the description of quantum states of photons and qudits. We show that the no-signaling property exists for both tomograms of two-mode states of photons and two-qudit states (two-spin states). We point out that there exists an ambiguity in the tomographic description of qudit states. We demonstrate that the single-qudit-state tomograms, corresponding to the ambiguity in the map of the state density matrix onto the tomographic-probability distribution, have a no-signaling property analogous to the property of the two-qudit-state tomogram.