Lau, Hoi Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 208-212). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Gravitational wave astronomy --- p.1 / Chapter 1.2 --- Stellar pulsation and gravitational radiation --- p.3 / Chapter 1.3 --- Outline --- p.5 / Chapter 2 --- Hydrostatic stellar structure --- p.8 / Chapter 2.1 --- Structural equation --- p.9 / Chapter 3 --- Finite temperature equations of state of nuclear matter --- p.13 / Chapter 3.1 --- Finite temperature ordinary nuclear matter --- p.13 / Chapter 3.2 --- Strange Quark Matter --- p.15 / Chapter 3.3 --- Equilibrium and Dynamic EOS --- p.16 / Chapter 4 --- Stellar pulsation and gravitational radiation --- p.19 / Chapter 4.1 --- Linearized theory of general relativity --- p.19 / Chapter 4.2 --- Stellar oscillation --- p.25 / Chapter 4.3 --- Quasi-normal Mode --- p.28 / Chapter 4.3.1 --- f mode --- p.29 / Chapter 4.3.2 --- p mode --- p.29 / Chapter 4.3.3 --- g mode --- p.30 / Chapter 4.3.4 --- w mode --- p.31 / Chapter 5 --- Gravitational wave spectrum of hot compact stars --- p.32 / Chapter 5.1 --- Numerical results --- p.32 / Chapter 5.1.1 --- Temperature effect on QNM --- p.32 / Chapter 5.1.2 --- Temperature effect and QS model --- p.38 / Chapter 5.1.3 --- QNM shift due to phase transition --- p.41 / Chapter 5.2 --- Summary and prospective --- p.48 / Chapter 6 --- Universality of fundamental mode and spacetime mode --- p.50 / Chapter 6.1 --- Review --- p.50 / Chapter 6.2 --- Generic proposal of universalities --- p.53 / Chapter 6.2.1 --- Moment of Inertia --- p.54 / Chapter 6.2.2 --- Gravitational wave spectrum --- p.57 / Chapter 6.3 --- Universality on moment of inertia --- p.63 / Chapter 6.4 --- Origin of universality --- p.70 / Chapter 6.4.1 --- Tolman VII model --- p.71 / Chapter 6.4.2 --- Polytropic Model --- p.76 / Chapter 6.5 --- Application of universality --- p.82 / Chapter 6.6 --- Summary --- p.89 / Chapter 7 --- Quark star properties and gravity mode oscillation --- p.92 / Chapter 7.1 --- Introduction --- p.92 / Chapter 7.2 --- g mode frequencies of quark stars --- p.94 / Chapter 7.2.1 --- Temperature profile and p mode frequency --- p.96 / Chapter 7.2.2 --- Strange quark mass and Yp mode frequency --- p.104 / Chapter 7.3 --- Summary --- p.108 / Chapter 8 --- Gravitational radiation excitation by infalling shell --- p.111 / Chapter 8.1 --- Introduction --- p.111 / Chapter 8.2 --- Formalism --- p.116 / Chapter 8.2.1 --- Connection between star and vacuum --- p.117 / Chapter 8.2.2 --- Matter source --- p.121 / Chapter 8.2.3 --- Geodesic --- p.124 / Chapter 8.2.4 --- Source of infalling dust shell --- p.126 / Chapter 8.2.5 --- Green's function --- p.127 / Chapter 8.3 --- Gravitational Wave excitation by collapsing shell --- p.130 / Chapter 8.4 --- Features of radiation --- p.138 / Chapter 8.4.1 --- Power spectrum --- p.138 / Chapter 8.4.2 --- Wave function --- p.144 / Chapter 8.4.3 --- Energy of excitation --- p.147 / Chapter 8.5 --- Non-adiabatic oscillation --- p.153 / Chapter 8.5.1 --- Mathematical Background --- p.154 / Chapter 8.5.2 --- Numerical results --- p.158 / Chapter 8.6 --- General relativistic simulation --- p.163 / Chapter 8.6.1 --- Technical briefing --- p.163 / Chapter 8.6.2 --- Numerical results --- p.166 / Chapter 8.7 --- Summary --- p.174 / Chapter 9 --- Conclusion and remarks --- p.178 / Chapter A --- Unit conversions --- p.183 / Chapter B --- Series expansion of quark star EOS --- p.185 / Chapter C --- Accuracy of simplified mode extraction scheme --- p.188 / Chapter D --- Computation of moment of inertia --- p.193 / Chapter E --- Comment of exactness of inference scheme --- p.195 / Chapter E.1 --- Precision of the mass inferred --- p.195 / Chapter E.2 --- Accuracy of universality combinations --- p.199 / Chapter F --- Calculation of sound speed --- p.202 / Chapter G --- Mode extraction of non-adiabatic oscillation --- p.204 / Bibliography --- p.208

M.Sc. / This project involves the analysis of data obtained through membership of the Kepler Asteroseismic Science Consortium Working Group 9, viz. proprietary data received from the Kepler Space Telescope. In this work, Kepler data on KIC011175495 are de-trended, and subject to a lengthy iteration of refined and sophisticated analysis routines, using many software platforms based on sound physical principles. The iteration is shown to converge to final values for the binary parameters and the pulsation frequencies present in the system. Conclusions are made on the interpretation of these results and the way forward for further analysis of this and related systems.

M.Sc. / Just as the observations of oscillations of ordinary stars can be used to determine their composition and structure, the oscillations of neutron stars could potentially be used to determine the nature of the dense nuclear matter from which they are made. The superfluidity of the interiors of neutron stars is normally probed by observations of pulsar glitches. It turns out that the superfluidity affects the oscillations in a neutron star core. In particular, it results in a class of oscillation modes specifically associated with the superfluid core. Although these modes have not been detected from observations, it is hoped by some that gravitational wave data may be used to probe the superfluidity of neutron star cores. In this dissertation, a simple equilibrium model is used in order to calculate the superfluid modes in the context of newtonian gravity. The equilibrium model that is used is the same combination of the Serot equation of state and the Harrison-Wheeler equation of state that was used formerly by Lee and by Lindblom & Mendell. Numerical calculations of the superfluid modes are done for 20 different neutron star models ranging in mass between 0.5 and 2 solar masses. The frequencies of the oscillations for the 0.5 and 1.4 solar masses agree fairly well with Lee's results, which strongly validates the computer code written for numerical calculation in this work. In all the models, the eigenfrequencies of the super uid or s-modes are found among those of the f and p-modes. For the equation of state that is used, it is shown that the dimensionless frequencies of the p-modes increase with an increase in mass of the neutron star while those of the s-modes decrease with an increase in neutron star mass. The plan of the dissertation is as follows. Chapter 1 gives a short introduction to stellar oscillations and mentions the oscillations of neutron stars. Chapters 2 and 3 provide the general theoretical background of stellar structure and stellar oscillations respectively. Chapter 4 is a review of the equations of state of neutron star matter derived previously in the literature. Chapter 5 provides the method of calculation as well as the results. Chapter 6 provides a discussion of the results. Chapter 7 briefly gives a review of a mathematical framework for fluids that could be used in order to calculate the oscillations in a general relativistic context and then briefly describes the effects of rotation and magnetic fields. Appendix B liststhe source code for the programs used to do the calculations and also explains some of the extra numerical procedures used for the computation.

Zhang, Yaojun = / "November 2009." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (p. 109-111). / Abstracts in English and Chinese. / Zhang, Yaojun = / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Quasi-Normal Modes of Neutron Stars --- p.6 / Chapter 2.1 --- Equilibrium State of a Neutron Star --- p.6 / Chapter 2.2 --- Fluid Displacement and Metric Perturbation --- p.8 / Chapter 2.3 --- Axial Oscillations of Neutron Stars --- p.9 / Chapter 2.3.1 --- Wave Equation inside the Star --- p.9 / Chapter 2.3.2 --- Wave Equation outside the Star --- p.10 / Chapter 2.3.3 --- Location of Quasi-normal Modes --- p.10 / Chapter 2.4 --- Polar Oscillations of Neutron Stars - LD Formalism --- p.12 / Chapter 2.4.1 --- Equations inside the Star --- p.12 / Chapter 2.4.2 --- Equations outside the Star --- p.14 / Chapter 2.4.3 --- Location of Quasi-normal Modes --- p.16 / Chapter 2.5 --- Polar Oscillations of Neutron Stars - AAKS Formalism --- p.16 / Chapter 2.5.1 --- Equations inside the Star --- p.16 / Chapter 2.5.2 --- Equations outside the Star --- p.19 / Chapter 2.5.3 --- Location of Quasi-normal Modes --- p.19 / Chapter 3 --- Decoupling of Spacetime Oscillations and Fluid Motion --- p.21 / Chapter 3.1 --- Motivation of Decoupling --- p.21 / Chapter 3.2 --- Expressing F in terms of S and H --- p.21 / Chapter 3.2.1 --- Inside the Star --- p.22 / Chapter 3.2.2 --- Outside the Star --- p.25 / Chapter 3.3 --- Constraint-free AAKS Formalism --- p.25 / Chapter 3.3.1 --- Equations inside the Star --- p.25 / Chapter 3.3.2 --- Equations outside the Star --- p.27 / Chapter 3.4 --- Cowling Approximation for Polar p-Mode --- p.29 / Chapter 3.4.1 --- Independent Fluid Motion --- p.29 / Chapter 3.4.2 --- Location of Polar p-Modes --- p.30 / Chapter 3.4.3 --- Numerical Results and Discussion --- p.31 / Chapter 3.5 --- Inverse-Cowling approximation for ω-Mode --- p.33 / Chapter 3.5.1 --- Independent Spacetime Oscillations --- p.33 / Chapter 3.5.2 --- Location of ω-Modes --- p.34 / Chapter 3.5.3 --- Numerical Results and Discussion --- p.34 / Chapter 4 --- Interplay between Matter and Spacetime --- p.37 / Chapter 4.1 --- Physical Insight --- p.37 / Chapter 4.2 --- Sturm-Liouville Eigenvalue Problem --- p.39 / Chapter 4.3 --- Energy of the Fluid --- p.40 / Chapter 4.4 --- Spacetime Oscillation Driven by Fluid Motion --- p.45 / Chapter 4.5 --- Damped Oscillation Caused by Radiation of Gravitational Wave --- p.46 / Chapter 4.6 --- Calculation of δωn in a Perturbative Way --- p.48 / Chapter 4.7 --- Numerical Results and Discussion --- p.49 / Chapter 5 --- Asymptotic Behavior of Spacetime Modes --- p.61 / Chapter 5.1 --- Motivation --- p.61 / Chapter 5.2 --- Asymptotic Behavior of Axial ω-modes for One-Layered Stars --- p.62 / Chapter 5.2.1 --- "Asymptotic Form of g(r*,ω)" --- p.63 / Chapter 5.2.2 --- "Asymptotic Form of f(r*, ω)" --- p.67 / Chapter 5.2.3 --- Asymptotic Behavior of Axial Quasi-Normal Modes --- p.69 / Chapter 5.3 --- Asymptotic Behavior of Polar ω-modes for One-Layered Stars --- p.71 / Chapter 5.3.1 --- High-Frequency Approximation --- p.71 / Chapter 5.3.2 --- Asymptotic Behavior of Polar Quasi-Normal Modes --- p.73 / Chapter 5.4 --- Relationship between Axial and Polar ω-Modes --- p.74 / Chapter 5.4.1 --- Application 1:ω-Modes of Quark Stars --- p.75 / Chapter 5.4.2 --- Application 2:ω-Modes of Polytropic Stars --- p.80 / Chapter 5.4.3 --- Application 3: The Influence of Surface Discontinuities --- p.89 / Chapter 5.4.4 --- Application 4:ω-Modes of Realistic Neutron Stars --- p.92 / Chapter 6 --- Conclusion and Outlook --- p.99 / Chapter A --- From Einstein Equation to LD Formalism --- p.101 / Chapter A.l --- The Linearized Perturbation Equations --- p.101 / Chapter A.1.1 --- The Perturbation of the Einstein Tensor --- p.102 / Chapter A.1.2 --- The Perturbation of the Energy-momentum Tensor --- p.103 / Chapter A.1.3 --- The Perturbed Einstein Equations --- p.104 / Chapter A.2 --- Some Symbolic Operation Results --- p.105 / Chapter A.3 --- Simplifications --- p.106

The objective of this thesis is to study the fluid oscillation modes in compact stars, understand their properties and infer stellar structures from their frequencies. The first part of the thesis focuses on the Newtonian theory of stellar pulsation and the Cowling approximation (CA), which neglects the change in gravitational potential. We modify the conventional CA, devise a more accurate version of the CA and calculate the first-order correction to the conventional CA. In the second part, we apply the variational approximation method proposed by Chandrasekhar [Astrophys. J. 139,664 (1963)] and δ-perturbation expansion proposed by Bender et. al. [J. Maths. Phys. 30, 1447 (1989)] to explain the universality in the relationships between the fundamental mode frequency and the moment of inertia of neutron stars, which was discovered by Lau et. al. [Astrophys. J. 714, 1234 (2010)]. We reveal that stiff equations of state are the conditions for the observed universality. In the third part, we consider the relativistic pulsation formulation and relativistic CAs for compact stars. We unify several known CAs with a single second-order differential equation. We also extend the modified CA derived from the formalism established by Allen et. al. [Phys. Rev. D 58, 124012 (1998)] to include the effect of buoyancy. Finally, we find the first-order and the second-order post-Newtonian expansions for the nonradial pulsations in quark stars. We derive an analytic formula expressing the fundamental mode frequency in terms of the compactness of quark stars. As a result, we are able to verify the universality mentioned above for quark stars. / 這論文是對在牛頓力學以及相對論框架下緻密星流體振盪的研究結果。論文第一部分集中討論牛頓力學下流體振盪以及近似方法。這近似方法忽略重力勢的擾動，令系統由四階微分方程減少為二階微分方程。我們修正了已往的近似方法和提出一個更精準的近似方法。第二部分包括變分近似方法。我們利用該方法和δ微擾理論解釋基本模式頻率的普通性。第三部分包括相對論框架下緻密星流體振盪和近似方法。我們以一條二階微分方程總結之前出現的近似方法並且在近似方法中加入浮力。最後，我們執行一階和二階的後牛頓展開，以分析夸克星的基本模式。我們驗證了展開的準確度和發現了基本模式頻率的方程。 / Chan, Tsang Keung = 有關在緻密星中流體振盪的研究 / 陳增強. / Thesis M.Phil. Chinese University of Hong Kong 2013. / Abstracts also in Chinese. / Title from PDF title page (viewed on 07, October, 2016). / Chan, Tsang Keung = You guan zai zhi mi xing zhong liu ti zhen dang de yan jiu / Chen Zengqiang. / Detailed summary in vernacular field only.

Not available / text

There is no abstract available for this thesis. / Department of Physics and Astronomy

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: D.E. Winget. Vita. Includes bibliographical references. Also available from UMI.

M.Sc. / The content of this dissertation is directed at a clearer understanding of pulsar behaviour. Pulsars are neutron stars in relatively early stages of their evolution. The intervals between observed arrival times of pulsar beams have been observed to suddenly decrease implying an increase in the star’s angular velocity Ω. This phenomenon is called a glitch. The first observed glitch occurred in the Vela pulsar (PSR 0833 -45) in 1969. The largest observed glitch also occurred in the Vela pulsar and exhibited a relative spin-up, Ω∕Ω~10−6 [1]. These relative pulsar spin-ups generally fall within the range 10−9 to 10−6 [2]. Pulsar glitches occur as a result of the processes in the interior of a neutron star [3]. Thus, a rigorous study of neutron star interiors is justified. Neutron star interiors are composed of hadronic matter: mostly neutrons, with a few per cent of protons (and, of course, non-hadronic electrons to conserve electric charge). The density of a neutron star interior increases with increasing depth as illustrated in 1.1.

In this work, the effect of rotation on the oscillation frequencies of some radially and nonradially oscillating Delta-Scuti stars have been explored. Rotation has been considered as a perturbation and treated up to the second order. Series of evolutionary models have been calculated for the oscillating stars in question and compared with the observational parameters. Three stars are considered: V350 Peg with no rotation, CC And with a rotational velocity Vsini=20 km/s, and BS Tuc with Vsini=130 km/s. We find that splitting in the oscillation frequencies are conspicuous especially in fast rotating stars, with a considerable contribution from the related terms due to second order effect.