Many growing networks possess accelerating statistics where the number of links added with each new node is an increasing function of network size so the total number of links increases faster than linearly with network size. In particular, biological networks can display a quadratic growth in regulator number with genome size even while remaining sparsely connected. These features are mutually...

We present observations of the first two supernovae discovered with the recently installed Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). The supernovae were found in Wide Field Camera images of the Hubble Deep Field North taken with the F775W, F850LP, and G800L optical elements as part of the ACS guaranteed time observation program. Spectra extracted from the ACS G800L ...

There has been much experimental and theoretical interest in blowout regime of plasma wakefield acceleration (PWFA), which features ultra-high accelerating fields, linear transverse focusing forces, and nonlinear plasma motion. Using an exact analysis, we examine here a fundamental limit of nonlinear PWFA excitation, by an infinitesimally short, relativistic electron beam. The beam energy loss ...

We examine selective reflection (SR) spectrum of an Airy beam at an interface between a dielectric and a homogeneous atomic medium. It is shown that both the general reflection (GR) and the SR of Airy beams exhibit accelerating dynamics with a parabolic trajectory, however, the accelerating rate for the SR is slightly greater than that for the GR. Due to interaction of atoms and the Airy beams ...

We demonstrate the generation of self-accelerating surface plasmon beams along arbitrary caustic curvatures. These plasmonic beams are excited by free-space beams through a two-dimensional binary plasmonic phase mask, which provides the missing momentum between the two beams in the direction of propagation and sets the required phase for the plasmonic beam in the transverse direction. We examin...

It has very recently been demonstrated by Csáki, Kaloper and Terning (CKT) that the faintness of supernovae at high redshift can be accommodated by mixing of a light axion with the photon in the presence of an intergalactic magnetic field, as opposed to the usual explanation of an accelerating universe by a dark energy component. In this paper we analyze further aspects of the CKT mechanism and...

We present a simple model where photons propagating in extragalactic magnetic fields can oscillate into very light axions. The oscillations may convert some of the photons, departing a distant supernova, into axions, making the supernova appear dimmer and hence more distant than it really is. Averaging over different configurations of the magnetic field we find that the dimming saturates at abo...

We investigated the effect of an accelerating field on the spin polarization of photogenerated electrons in a 100nm thick GaAs based photocathode active region. By decreasing the transport time of the electrons and the number of scattering events that cause depolarization, we expected to increase the polarization as was indicated by Monte Carlo simulations of the scattering and transport time s...

A high gradient cavity(HGC) using high permeability magnetic alloy (MA) cores has been developed at KEK for the JHF(Japan Hadron Facility) proton synchrotrons. In this paper, we describe two types of push-pull amplifiers to drive the cavity, which were constructed for verifying the cavity performance. An accelerating voltage of 20kV across the gap of the HGC was generated by the high power push...