Cosmology with unparticles
Bohdan Grzadkowski and Jose Wudka
We discuss cosmological consequences of the existence of physics beyond the standard model that exhibits Banks-Zaks and unparticle behavior in the UV and IR, respectively. We first derive the equation of state for unparticles and use it to obtain the temperature dependence of the corresponding energ ... [Phys. Rev. D 80, 103518 (2009)] published Fri Nov 20, 2009.
CMB lensing constraints on dark energy and modified gravity scenarios
Erminia Calabrese, Asantha Cooray, Matteo Martinelli, Alessandro Melchiorri, Luca Pagano et al.
Weak gravitational lensing leaves a characteristic imprint on the cosmic microwave background temperature and polarization angular power spectra. Here, we investigate the possible constraints on the integrated lensing potential from future cosmic microwave background angular spectra measurements exp ... [Phys. Rev. D 80, 103516 (2009)] published Thu Nov 19, 2009.
Holes in the static Einstein universe and a model of the cosmological voids
Andrzej Odrzywolek
A spherically symmetric, static model of the cosmological voids is constructed in the framework of the Tolman-Oppenheimer-Volkov equation with the cosmological constant. Extension of the Tooper result (dimensionless form of the TOV equation) is provided for nonzero Lambda. Then, the equation is simp ... [Phys. Rev. D 80, 103515 (2009)] published Tue Nov 17, 2009.
Assisted dark energy
Junko Ohashi and Shinji Tsujikawa
Cosmological scaling solutions, which give rise to a scalar-field density proportional to a background fluid density during radiation and matter eras, are attractive to alleviate the energy scale problem of dark energy. In the presence of multiple scalar fields, the scaling solution can exit to the ... [Phys. Rev. D 80, 103513 (2009)] published Mon Nov 16, 2009.
Sensitivity of cosmic-ray experiments to ultrahigh-energy photons: Reconstruction of the spectrum and limits on the superheavy dark matter
O. E. Kalashev, G. I. Rubtsov, and S. V. Troitsky
We estimate the sensitivity of various experiments detecting ultrahigh-energy cosmic rays to primary photons with energies above 10 eV. We demonstrate that the energy of a primary photon may be significantly (up to a factor of ~10) underestimated or overestimated for particular primary energies and ... [Phys. Rev. D 80, 103006 (2009)] published Mon Nov 16, 2009.
Constraint on coupled dark energy models from observations
Jun-Qing Xia
The coupled dark energy models, in which the quintessence scalar field nontrivially couples to the cold dark matter, have been proposed to explain the coincidence problem. In this paper we study the perturbations of coupled dark energy models and the effects of this interaction on the current observ ... [Phys. Rev. D 80, 103514 (2009)] published Mon Nov 16, 2009.
Inflaton two-point correlation in the presence of a cosmic string
Chien-Yao Tseng and Mark B. Wise
Precise measurements of the microwave background anisotropy have confirmed the inflationary picture of approximately scale invariant, Gaussian primordial adiabatic density perturbations. However, there are some anomalies that suggest a small violation of rotational and/or translational invariance in ... [Phys. Rev. D 80, 103512 (2009)] published Fri Nov 13, 2009.
A New Approach to the Coronal Heating Problem
J. Vranjes and S. Poedts
The heating of the solar corona is discussed within both frameworks of kinetic and fluid drift wave theory. It is shown that the basic ingredient necessary for the heating is the presence of the background density gradients in the direction perpendicular to the magnetic field vector. These gradients ... [AIP Conf. Proc. 1188, 153 (2009)] published Thu Nov 12, 2009.
Dust Destruction in a Nonradiative Shock in the Cygnus Loop Supernova Remnant
Ravi Sankrit, Brian J. Williams, Kazimierz J. Borkowski, John C. Raymond, Terrance J. Gaetz et al.
We present 24 [mu]m and 70 [mu]m images of a non-radiative shock in the Cygnus Loop supernova remnant, obtained with the Multiband Imaging Photometer on board the Spitzer Space Telescope. The observed emission is from dust grains heated in the post-shock region. The 70 [mu]m to 24 [mu]m flux ratio d ... [AIP Conf. Proc. 1183, 95 (2009)] published Thu Nov 12, 2009.
Drift Kinetic Theory and Cosmic Rays
G. M. Webb, J. A. le Roux, and G. P. Zank
Starting from the Vlasov or Boltzmann equation for cosmic rays in a random and regular magnetic field, we introduce guiding center coordinates and transform the velocity to a frame moving at the electric field drift velocity. The resultant equation is written in terms of the parallel and perpendicul ... [AIP Conf. Proc. 1183, 85 (2009)] published Thu Nov 12, 2009.
Particle Acceleration at Relativistic Shocks in Extragalactic Systems
Matthew G. Baring and Errol J. Summerlin
Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma ray bursts. These sources remain strong and interesting candidate sites for the gener ... [AIP Conf. Proc. 1183, 74 (2009)] published Thu Nov 12, 2009.
Wave Dynamics and Particle Acceleration in Shock Precursors
M. A. Malkov and P. H. Diamond
Cosmic ray protons accelerated in strong shocks are known to drive various instabilities in the shock precursor. An acoustic instability of the shock precursor driven by the pressure gradient of accelerated particles is studied in the nonlinear regime. After nonlinear steepening of the unstable wave ... [AIP Conf. Proc. 1183, 66 (2009)] published Thu Nov 12, 2009.
Non-linear Guiding Center Theory and Acceleration of Cosmic Rays at Supernova Remnant Shocks
G. Li, G. Webb, A. Shalchi, and G. P. Zank
Supernova Remnant shocks have long been identified as the major site of cosmic ray acceleration. At the shock front, cosmic rays traverse upstream and downstream multiple times and gain energies up to 10 eV and perhaps even reach 10 eV. The maximum achievable energy at a SNR shock is decided by many ... [AIP Conf. Proc. 1183, 57 (2009)] published Thu Nov 12, 2009.
Termination Shock Surfing
R. H. Burrows, G. P. Zank, and G. M. Webb
The recent Voyager 2 (V2) observations of the termination shock (TS) indicate that it is a plasma shock like no other in the heliosphere with dynamics and structure heavily influenced by the presence of an energized population of pickup ions (PUIs). The `unexpected' finding of a cold plasma in the h ... [AIP Conf. Proc. 1183, 47 (2009)] published Thu Nov 12, 2009.
Interaction of turbulence with oblique MHD shocks
X. Ao and G. P. Zank
An analytic model developed by Ao et al.[1] describes the interaction of turbulence with a thin MHD shock. The interaction is governed by a modified Burgers' equation. In this paper, we solve the modified Burgers' equation numerically for arbitrary oblique MHD shocks. Starting with the classical ide ... [AIP Conf. Proc. 1183, 220 (2009)] published Thu Nov 12, 2009.
On the Source of the Anomalous Cosmic Rays
R. Kallenbach, K. Bamert, and M. Hilchenbach
In the years 2004 and 2007, the instruments onboard the Voyager 1&2 spacecraft delivered unprecedented data on the structure of the solar wind termination shock. This shock has been assumed to be responsible for the acceleration of the anomalous component of cosmic rays (ACRs) from a pick-up ion see ... [AIP Conf. Proc. 1183, 212 (2009)] published Thu Nov 12, 2009.
Particle Motion and Energization in a Chaotic Magnetic Field
G. Li, B. Dasgupta, G. Webb, and A. K. Ram
In nature there are many systems where macroscopic and time varying currents exist. For example, in solar flares, currents in the form of filaments and/or loops have been observed. In a simple asymmetric configuration where steady state currents flow through a straight wire and a loop, a somewhat su ... [AIP Conf. Proc. 1183, 201 (2009)] published Thu Nov 12, 2009.
Physics of relativistic shocks
Mikhail V. Medvedev
Relativistic shocks are usually thought to occur in violent astrophysical explosions. These collisionless shocks are mediated by a plasma kinetic streaming instability, often loosely referred to as the Weibel instability, which generates strong magnetic fields from scratch very efficiently. In this ... [AIP Conf. Proc. 1183, 189 (2009)] published Thu Nov 12, 2009.
Generation and Evolution of Interplanetary Shocks
Chin-Chun Wu
Timing and locating interplanetary (IP) shocks in the heliosphere constitutes a major task in space weather forecasting, as they are source of solar energetic particles and the leading signal of an upcoming magnetic cloud/interplanetary coronal mass ejection (MC/ICME) that causes major geomagnetic a ... [AIP Conf. Proc. 1183, 178 (2009)] published Thu Nov 12, 2009.
Shock Waves in Space Environments
Devrie S. Intriligator, Thomas Detman, James Intriligator, Christine Gloeckler, Wei Sun et al.
We present results on two topics: a) The three-dimensional (3D) Hybrid Heliospheric Modeling System with Pickup Ions (HHMS-PI) simulations of shock waves and initial comparisons with ACE and Ulysses data for the Halloween 2003 solar events, including the Ulysses SWICS pickup proton densities; and b) ... [AIP Conf. Proc. 1183, 167 (2009)] published Thu Nov 12, 2009.
Micro-Structure of the Heliospheric Termination Shock
G. P. Zank, R. Burrows, M. Oka, B. Dasgupta, J. Heerikhuisen et al.
Observations by the Voyager 2 spacecraft of the structure of the heliospheric termination shock revealed a quasi-perpendicular structure that possessed many of the characteristics that are familiar to us from perpendicular shocks observed in the inner heliosphere. However, a surprise was the relativ ... [AIP Conf. Proc. 1183, 156 (2009)] published Thu Nov 12, 2009.