scholarly journals Determination of the internal structure of neutron stars from gravitational wave spectra

2006 ◽  
Vol 74 (12) ◽  
Author(s):  
L. K. Tsui ◽  
P. T. Leung ◽  
J. Wu
Keyword(s):  
Neutron Stars ◽  
Gravitational Wave ◽  
Internal Structure ◽  
Wave Spectra

scholarly journals Pulsar Identification of Background Spectra of LIGO Data

2018 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Black Holes ◽  
Exact Solution ◽  
General Relativity ◽  
Time Delay ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Compact Objects ◽  
Gravitational Redshift ◽  
Wave Spectra

By choosing the metric (called physical metric) in general relativity as the exact solution to the Einstein equation that fits the time delay data, one can determine the size and gravitational redshift on the surface of compact objects (neutron stars and black holes). The author shows that the physical metric is invariant by rotation. As a result, the frequencies of gravitational waves from pulsars are represented as n * f / for pulsar frequency f and harmonics n. Based on this result, the author has identified potential pulsar candidates with gravitational wave spectra. This result will be critical in the study of gravitational redshift of compact objects.

scholarly journals A Gravitational-Wave Perspective on Neutron-Star Seismology

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 97
Author(s):  
Nils Andersson
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Fundamental Mode ◽  
Compact Binaries

We provide a bird’s-eye view of neutron-star seismology, which aims to probe the extreme physics associated with these objects, in the context of gravitational-wave astronomy. Focussing on the fundamental mode of oscillation, which is an efficient gravitational-wave emitter, we consider the seismology aspects of a number of astrophysically relevant scenarios, ranging from transients (like pulsar glitches and magnetar flares), to the dynamics of tides in inspiralling compact binaries and the eventual merged object and instabilities acting in isolated, rapidly rotating, neutron stars. The aim is not to provide a thorough review, but rather to introduce (some of) the key ideas and highlight issues that need further attention.

scholarly journals Energy budget and the gravitational wave spectra beyond the bag model

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Xiao Wang ◽  
Fa Peng Huang ◽  
Xinmin Zhang
Keyword(s):  
Gravitational Wave ◽  
Energy Budget ◽  
Wave Spectra ◽  
Bag Model

scholarly journals Neutron stars as probes of dark matter

2020 ◽  
Vol 29 (14) ◽  
pp. 2043028
Author(s):  
M. Ángeles Pérez-García ◽  
Joseph Silk
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Equation Of State ◽  
Neutron Stars ◽  
Internal Structure ◽  
Stellar Objects ◽  
Ordinary Matter ◽  
Stable Solutions ◽  
The Universe

Neutron Stars (NSs) are compact stellar objects that are stable solutions in General Relativity. Their internal structure is usually described using an equation of state that involves the presence of ordinary matter and its interactions. However there is now a large consensus that an elusive sector of matter in the universe, described as dark matter, remains as yet undiscovered. In such a case, NSs should contain both, baryonic and dark matter. We argue that depending on the nature of the dark matter and in certain circumstances, the two matter components would form a mixture inside NSs that could trigger further changes, some of them observable. The very existence of NSs constrains the nature and interactions of dark matter in the universe.

scholarly journals Structure investigations of layered soil – varved clay

2016 ◽  
Vol 48 (4) ◽  
pp. 365-375 ◽  
Author(s):  
Matylda Tankiewicz
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Strength Properties ◽  
Layered Soil ◽  
Radiographic Images ◽  
Composition And Structure ◽  
Computed Microtomography ◽  
Structure Investigations ◽  
Varved Clay

Abstract In the paper the results of laboratory investigations of structure of layered soil are presented. They focus on varved clay that is a soil composed of two alternately arranged varves with different texture and mechanical properties. An effect of such structure is an anisotropy of the material. Due to varying conditions during its formation process the soil exhibits some irregularities in composition and structure. Due to that modelling of mechanical behavior, like strength, may not provide satisfactory results. Main purpose of the examinations is an investigation of internal structure of layered soil – varved clay – in relation to its strength anisotropy and evaluation of the suitability of the use of two different techniques to assess the soil structure. Investigated material have been taken from area near city of Bełchatów in central Poland. The examinations included investigation of particle size distribution of soil and its components, identification of lamination with use of scanning electron microscope (SEM) and computed microtomography technique (μCT). First, the texture of each varve and varved clay as a composite have been estimated. Next, the investigation of surface perpendicular to the lamination have been carried out with SEM. Pictures of varves with different magnifications are presented. Also the varves arrangement and details of layers contact area are shown. Finally, investigation of internal structure of the soil have been performed by using microtomograph. The outcome is a series of radiographic images and reconstructed 3D model of tested soil. Presented results show complexity of the structure of varved clay that affect the mechanical behavior. Determination of the structure with use of presented techniques may be helpful in examination of strength properties and proper modeling of such soil.

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