266 research outputs found

    Evolution of non-stationary pulses in a cold magnetized quark-gluon plasma

    Full text link
    We study weakly nonlinear wave perturbations propagating in a cold nonrelativistic and magnetized ideal quark-gluon plasma. We show that such perturbations can be described by the Ostrovsky equation. The derivation of this equation is presented for the baryon density perturbations. Then we show that the generalized nonlinear Schr{\"o}dinger (NLS) equation can be derived from the Ostrovsky equation for the description of quasi-harmonic wave trains. This equation is modulationally stable for the wave number k<kmk < k_m and unstable for k>kmk > k_m, where kmk_m is the wave number where the group velocity has a maximum. We study numerically the dynamics of initial wave packets with the different carrier wave numbers and demonstrate that depending on the initial parameters they can evolve either into the NLS envelope solitons or into dispersive wave trains

    Similarities between interstitial cystitis/bladder pain syndrome and vulvodynia: implications for patient management

    Get PDF
    Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies

    Energy transfer dynamics and thermalization of two oscillators interacting via chaos

    Full text link
    We consider the classical dynamics of two particles moving in harmonic potential wells and interacting with the same external environment (HE), consisting of N non-interacting chaotic systems. The parameters are set so that when either particle is separately placed in contact with the environment, a dissipative behavior is observed. When both particles are simultaneously in contact with HE an indirect coupling between them is observed only if the particles are in near resonance. We study the equilibrium properties of the system considering ensemble averages for the case N=1 and single trajectory dynamics for N large. In both cases, the particles and the environment reach an equilibrium configuration at long times, but only for large N a temperature can be assigned to the system.Comment: 8 pages, 6 figure

    Loop expansion in Yang-Mills thermodynamics

    Get PDF
    We argue that a selfconsistent spatial coarse-graining, which involves interacting (anti)calorons of unit topological charge modulus, implies that real-time loop expansions of thermodynamical quantities in the deconfining phase of SU(2) and SU(3) Yang-Mills thermodynamics are, modulo 1PI resummations, determined by a finite number of connected bubble diagrams.Comment: 15 pages, 2 figures, v5: discussion of much more severely constrained nonplanar situation included in Sec.

    Identification and quantification of dolichol and dolichoic acid in neuromelanin from substantia nigra of the human brain.

    Get PDF
    Neuromelanin (NM) isolated from the substantia nigra of the human brain is found to contain a series of dolichoic acids (dol-CA) containing 14–20 isoprene units. This is the first observation of dol-CA in a natural system. Using internally spiked nor-dolichol and nor-dolichoic acid standards, the concentrations of dolichol (dol) and dol-CA present in NM were determined. Remarkably, dol was only four times as abundant as dol-CA in NM. The distribution of dol-CA chains lengths in NM also differed from that of dol, suggesting that the enzyme(s) responsible for the conversion of dol to dol-CA prefer a dolichol substrate containing 19 isoprene units

    A Planck-scale axion and SU(2) Yang-Mills dynamics: Present acceleration and the fate of the photon

    Full text link
    From the time of CMB decoupling onwards we investigate cosmological evolution subject to a strongly interacting SU(2) gauge theory of Yang-Mills scale Λ∌10−4\Lambda\sim 10^{-4} eV (masquerading as the U(1)YU(1)_{Y} factor of the SM at present). The viability of this postulate is discussed in view of cosmological and (astro)particle physics bounds. The gauge theory is coupled to a spatially homogeneous and ultra-light (Planck-scale) axion field. As first pointed out by Frieman et al., such an axion is a viable candidate for quintessence, i.e. dynamical dark energy, being associated with today's cosmological acceleration. A prediction of an upper limit ΔtmÎł=0\Delta t_{m_\gamma=0} for the duration of the epoch stretching from the present to the point where the photon starts to be Meissner massive is obtained: ΔtmÎł=0∌2.2\Delta t_{m_\gamma=0}\sim 2.2 billion years.Comment: v3: consequences of an error in evolution equation for coupling rectified, only a minimal change in physics results, two refs. adde
    • 

    corecore