5,314 research outputs found

    Galilean Limit of Equilibrium Relativistic Mass Distribution

    Full text link
    The low-temperature form of the equilibrium relativistic mass distribution is subject to the Galilean limit by taking c.c\rightarrow \infty . In this limit the relativistic Maxwell-Boltzmann distribution passes to the usual nonrelativistic form and the Dulong-Petit law is recovered.Comment: TAUP-2081-9

    Generalized Boltzmann Equation in a Manifestly Covariant Relativistic Statistical Mechanics

    Get PDF
    We consider the relativistic statistical mechanics of an ensemble of NN events with motion in space-time parametrized by an invariant ``historical time'' τ.\tau . We generalize the approach of Yang and Yao, based on the Wigner distribution functions and the Bogoliubov hypotheses, to find the approximate dynamical equation for the kinetic state of any nonequilibrium system to the relativistic case, and obtain a manifestly covariant Boltzmann-type equation which is a relativistic generalization of the Boltzmann-Uehling-Uhlenbeck (BUU) equation for indistinguishable particles. This equation is then used to prove the HH-theorem for evolution in τ.\tau . In the equilibrium limit, the covariant forms of the standard statistical mechanical distributions are obtained. We introduce two-body interactions by means of the direct action potential V(q),V(q), where qq is an invariant distance in the Minkowski space-time. The two-body correlations are taken to have the support in a relative O(2,1)O( 2,1)-invariant subregion of the full spacelike region. The expressions for the energy density and pressure are obtained and shown to have the same forms (in terms of an invariant distance parameter) as those of the nonrelativistic theory and to provide the correct nonrelativistic limit

    Representation of Quantum Mechanical Resonances in the Lax-Phillips Hilbert Space

    Get PDF
    We discuss the quantum Lax-Phillips theory of scattering and unstable systems. In this framework, the decay of an unstable system is described by a semigroup. The spectrum of the generator of the semigroup corresponds to the singularities of the Lax-Phillips SS-matrix. In the case of discrete (complex) spectrum of the generator of the semigroup, associated with resonances, the decay law is exactly exponential. The states corresponding to these resonances (eigenfunctions of the generator of the semigroup) lie in the Lax-Phillips Hilbert space, and therefore all physical properties of the resonant states can be computed. We show that the Lax-Phillips SS-matrix is unitarily related to the SS-matrix of standard scattering theory by a unitary transformation parametrized by the spectral variable σ\sigma of the Lax-Phillips theory. Analytic continuation in σ\sigma has some of the properties of a method developed some time ago for application to dilation analytic potentials. We work out an illustrative example using a Lee-Friedrichs model for the underlying dynamical system.Comment: Plain TeX, 26 pages. Minor revision

    Construction of a Complete Set of States in Relativistic Scattering Theory

    Get PDF
    The space of physical states in relativistic scattering theory is constructed, using a rigorous version of the Dirac formalism, where the Hilbert space structure is extended to a Gel'fand triple. This extension enables the construction of ``a complete set of states'', the basic concept of the original Dirac formalism, also in the cases of unbounded operators and continuous spectra. We construct explicitly the Gel'fand triple and a complete set of ``plane waves'' -- momentum eigenstates -- using the group of space-time symmetries. This construction is used (in a separate article) to prove a generalization of the Coleman-Mandula theorem to higher dimension.Comment: 30 pages, Late

    The conservation status of freshwater macro-invertebrates in the Buckland Military Training Area, southeastern Tasmania

    Get PDF
    The freshwater macro-invertebrate fauna of the Buckland Military Training Area near Triabunna on the east coast of Tasmania was investigated in April 1991. A total of 97 taxa were identified from ten sites, of which only about half could be assigned to species level and given a conservation status. Only one of these was deemed significant from a conservation viewpoint; at least eight others plus all the unknown species require further investigation to clarify their status. About half of the species were found at only one site; the most similar sites were from permanent water at lower altitudes (although in different catchments). Species from lowland sites were well known and could be readily identified (often having broad distributional ranges over southeastern Australia).The upland site from a rainforest creek contained a high proportion of species not found elsewhere in the study, as did other upland temporary water bodies. Introduced fish and forestry activity are likely to represent the most serious threats to the faunal assemblage in the area

    Estimating proportions of objects from multispectral scanner data

    Get PDF
    Progress is reported in developing and testing methods of estimating, from multispectral scanner data, proportions of target classes in a scene when there are a significiant number of boundary pixels. Procedures were developed to exploit: (1) prior information concerning the number of object classes normally occurring in a pixel, and (2) spectral information extracted from signals of adjoining pixels. Two algorithms, LIMMIX and nine-point mixtures, are described along with supporting processing techniques. An important by-product of the procedures, in contrast to the previous method, is that they are often appropriate when the number of spectral bands is small. Preliminary tests on LANDSAT data sets, where target classes were (1) lakes and ponds, and (2) agricultural crops were encouraging

    Hypercomplex quantum mechanics

    Full text link
    The fundamental axioms of the quantum theory do not explicitly identify the algebraic structure of the linear space for which orthogonal subspaces correspond to the propositions (equivalence classes of physical questions). The projective geometry of the weakly modular orthocomplemented lattice of propositions may be imbedded in a complex Hilbert space; this is the structure which has traditionally been used. This paper reviews some work which has been devoted to generalizing the target space of this imbedding to Hilbert modules of a more general type. In particular, detailed discussion is given of the simplest generalization of the complex Hilbert space, that of the quaternion Hilbert module.Comment: Plain Tex, 11 page

    Towards a Realistic Equation of State of Strongly Interacting Matter

    Full text link
    We consider a relativistic strongly interacting Bose gas. The interaction is manifested in the off-shellness of the equilibrium distribution. The equation of state that we obtain for such a gas has the properties of a realistic equation of state of strongly interacting matter, i.e., at low temperature it agrees with the one suggested by Shuryak for hadronic matter, while at high temperature it represents the equation of state of an ideal ultrarelativistic Stefan-Boltzmann gas, implying a phase transition to an effectively weakly interacting phase.Comment: LaTeX, figures not include
    corecore