Cone-kernel representation versus instantaneous power spectrum

Hyperbolic kernel for time-frequency power spectrum

Light-cone effect on the reionization 21-cm power spectrum

Observations of redshifted 21-cm radiation from neutral hydrogen during the epoch of reionization are considered to constitute the most promising tool to probe that epoch. One of the major goals of the first generation of low-frequency radio telescopes is to measure the 3D 21-cm power spectrum. However, the 21-cm signal could evolve substantially along the lineof-sight (LOS) direction of an obs...

Kernel estimation of the instantaneous frequency

We consider kernel estimators of the instantaneous frequency of a slowly evolving sinusoid in white noise. The expected estimation error consists of two terms. The systematic bias error grows as the kernel halfwidth increases while the random error decreases. For a nonmodulated signal, g(t), the kernel halfwidth which minimizes the expected error scales as h ∼ [ σ2 N |∂2 t g |2 ]1/5 , where σ2 ...

Instantaneous Representation and the Pig Itself

Instantaneous representation offers the promise of showing reality itself, but as all representation removes context, it still relies on what are traditionally considered to be elements of writing, rather than existing in opposition to writing. Narrative is essential in any form of representation, as the proliferation of talk radio, ‘reality television’, docu-dramas, etc. shows. Virtual reality...

Instantaneous Spectrum Estimation of Event-Based Densities

We present a method for obtaining a time-varying spectrum that is particularly suited when the data are in event-based form. This form arises in many areas of science and engineering, and especially in astronomy, where one has photon counting detectors. The method presented consists of three procedures. First, estimating the density using the kernel method; second, highpass filtering the manife...