Astroparticle Physics

16 Glossary 331This theory refers to inertial non-accelerated frames of reference. Itassumes that physical laws are identical in all frames of referenceand that the speed of light in vacuum c is constant throughout theuniverse and independent of the speed of the observer. The theoremof the addition of velocities is modified to account for the deviationfrom the Galilei transformation.Intrinsic angular momentum of a particle quantized in units of ¯h,where ¯h =2π h and h is Planck’s constant.Emergence of different properties of a system at low energies (e.g.,weak and electromagnetic interaction) which do not exist at highenergies where these interactions are described by the Unified Theory.Supersymmetric partner of a quark.An astronomical object with well-known absolute luminosity whichcan be used to determine distances.Theory of fundamental particles and their interactions. Originallythe Standard Model described the unification of weak and electromagneticinteractions, the electroweak interaction. In a more generalsense it is used for the common description of weak, electromagnetic,and strong interactions.Galaxies with a high star-formation rate.A bunch of stars which are bound to each other by their mutualgravitational attraction.A quake in the crust of a neutron star.Older model of the universe in which matter is continuously producedto fill up the empty space created by expansion, therebymaintaining a constant density (‘steady-state universe’).This law states that the amount of energy radiated by a blackbodyis proportional to the fourth power of its temperature.The ejection of gas off the surface of a star.Synchrotron in which counter-rotating particles and antiparticlesare stored in a vacuum pipe. The particles usually stored in bunchescollide in interaction points, where the center of mass energy isequal to twice the beam energy for a head-on collision. Storagerings are used in particle physics and for experiments with synchrotronradiation.special theory of relativityspinspontaneous symmetry breakingsquarkstandard candleStandard Modelstarburst galaxiesstar clusterstar quakesteady-state universeStefan–Boltzmann lawstellar windstorage ring