Related papers: Radio timing in a millisecond pulsar-extreme/inter…
Pulsars are very stable clocks in space which have many applications to problems in physics and astrophysics. Observations of double-neutron-star binary systems have given the first observational evidence for the existence of gravitational…
The timing of millisecond pulsars has long been used as an exquisitely precise tool for testing the building blocks of general relativity, including the strong equivalence principle and Lorentz symmetry. Observations of binary systems…
Precision astrometry is an integral component of successful pulsar timing campaigns. Astrometric parameters are commonly derived by fitting them as parameters of a timing model to a series of pulse times of arrival (TOAs). TOAs measured to…
Detailed numerical analyses of the orbital motion of a test particle around a spinning primary are performed. They aim to investigate the possibility of using the post-Keplerian (pK) corrections to the orbiter's periods (draconitic,…
The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. We…
Pulsar timing uses the highly stable pulsar spin period to investigate many astrophysical topics. In particular, pulsar timing arrays make use of a set of extremely well-timed pulsars and their time correlations as a challenging detector of…
After large galaxies merge, their central supermassive black holes are expected to form binary systems whose orbital motion generates a gravitational wave background (GWB) at nanohertz frequencies. Searches for this background utilize…
Supermassive black hole binaries are promising sources of low-frequency gravitational waves (GWs) and bright electromagnetic emission. Pulsar timing array searches for resolved binaries are complex and computationally expensive and so far…
The extremely regular, periodic radio emission from millisecond pulsars makes them useful tools for studying neutron star astrophysics, general relativity, and low-frequency gravitational waves. These studies require that the observed pulse…
The detection of compact binary mergers with sub-solar masses at gravitational-wave observatories could mark the groundbreaking discovery of primordial black holes (PBHs). Concurrently, evidence for a nHz stochastic gravitational wave…
We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 years. It forms the basis for…
The discovery of radio pulsars in compact orbits around Sgr A* would allow an unprecedented and detailed investigation of the spacetime of the supermassive black hole. This paper shows that pulsar timing, including that of a single pulsar,…
We investigate rotational spin noise (referred to as timing noise) in non-accreting pulsars: millisecond pulsars, canonical pulsars, and magnetars. Particular attention is placed on quantifying the strength and non-stationarity of timing…
This thesis focuses on the study of binary radio pulsars, their evolution and some specific use of their properties to investigate fundamental physics such as general relativity and other gravitational theories. The work that we present…
Pulsar timing arrays (PTAs) are designed to detect the predicted gravitational wave (GW) background produced by a cosmological population of supermassive black hole (SMBH) binaries. In this contribution I review the physics of such GW…
The post-Newtonian approximation is a method for solving Einstein's field equations for physical systems in which motions are slow compared to the speed of light and where gravitational fields are weak. Yet it has proven to be remarkably…
We investigate the spin dynamics of a millisecond pulsar (MSP) in compact orbit around a Kerr-like massive black hole with an general mass quadrupole. We use the Mathisson-Papetrou-Dixon formulation to compute the orbital and spin evolution…
The discovery of radio pulsars (PSRs) around the supermassive black hole (SMBH) in our Galactic Center (GC), Sagittarius A* (Sgr A*), will have significant implications for tests of gravity. In this paper, we predict restrictions on the…
Orbital parameters of binary radio pulsars reveal the history of the pulsars' formation and evolution including dynamic interactions with other objects. Advanced technology has enabled us to determine these orbital parameters accurately in…
A powerful technique to calculate gravitational radiation from binary systems involves a perturbative expansion: if the masses of the two bodies are very different, the "small" body is treated as a point particle of mass $m_p$ moving in the…