Predictive state representations (PSRs) use predictions of a set of tests to represent the state of controlled dynamical systems. One reason why this representation is exciting as an alternative to partially observable Markov decision processes (POMDPs) is that PSR models of dynamical systems may be much more compact than POMDP models. Empirical work on PSRs to date has focused on linear PSRs, ...

The single-pulse properties of the millisecond radio pulsar PSR B1937+21 are studied in the 1410 MHz radio band. Aside from occasional “giant pulses” occurring in restricted regions of pulse phase, the emission appears to be remarkably stable, showing no pulse-to-pulse fluctuations other then those induced by propagation through the interstellar medium. This type of behavior has not been seen i...

The fastest millisecond pulsar PSR B1937+21 presents an interpulse separated from the main pulse by nealy 180 at radio frequencies. Recently, the ASCA observations (Takahashi et al. 2001) detected pulsed X-ray emission from this pulsar. Only a single narrow X-ray pulse is observed, which is coincident with the radio interpulse in phase. We investigate the validity of the polar cap (PC) model an...

The launch of several sensitive X-ray and γ-ray instruments during the last decade heralded a new era in the research of millisecond pulsars. The current number of millisecond pulsars detected in the X-ray spectral window is about 30, including those located in globular clusters, which represents a significant fraction of the total number of spin-down powered pulsars emitting high-energy radiat...

We present the results of deep, high-resolution, multi-band optical observations of the field of the young (∼ 5, 000 yrs) 16 ms X-ray pulsar PSR J0537−6910 performed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). Although a few new potential counterparts have been detected within or close to the revised Chandra X-ray error circle (≃ 1′′) of the pulsar, only ...

The recent discovery of rotating radio transients and the quasi-periodicity of pulsar activity in the radio pulsar PSR B1931+24 has challenged the conventional theory of radio pulsar emission. Here we suggest that these phenomena could be due to the interaction between the neutron star magnetosphere and the surrounding debris disk. The pattern of pulsar emission depends on whether the disk can ...

From the point of information theory, the baseband binary pulse amplitude modulated (PAM) signals transmission, via tuning the nonlinear receiver’s parameters, is studied over an additive white Gaussian noise (AWGN) channel. It is demonstrated that the channel capacity of baseband binary communication systems, for a given signal added noise, can be maximized by optimal designed receivers. This ...

We report the optical identification of the companion to the Fermi black widow millisecond pulsar PSR J1544+4937. We find a highly variable source on Keck LRIS images at the nominal pulsar position, with 2 magnitude variations over orbital period in the B, g, R, and I bands. The nearly achromatic light curves are difficult to explain with a simply irradiated hemisphere model, and suggest that t...

In this paper we try to dynamically constrain the quadrupole mass moment Q of the millisecond PSR B1257+12 pulsar from the orbital periods of its three planets, assumed to be in equatorial and circular orbits. Given the present-day accuracy in knowing their ephemerides, no post-Newtonian corrections to their motions are required. By conservatively assuming 1% and 10% uncertainties in the pulsar...

COMPTEL, aboard the Compton Gamma-Ray Observatory , has detected at MeV energies PSR B1951+32 and found indications for a signal from PSR B0656+14. In the combined COMPTEL { EGRET spectra it is apparent that the maximum luminosities of these objects are reached in the COMPTEL energy range, or at least spectral features/bumps are apparent. These spectra can be compared with those of four other p...