The Einstein's equations expressed in the form of eq. \ref{EE} are valid in the weak field (or Newtonian) approximation:
\begin{enumerate}
\item The motion of particles is non-relativistic.
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@@ -178,12 +179,12 @@ Fig. \ref{spec} summarizes the possible objects that can be gravitational waves
\end{figure}
\noindent
The best modelled sources are binary systems, typically Neutron stars (NS), White Dwarfs (WD) and Black Holes (BH), orbiting each other. Fig. \ref{binary} shows the main phases of the evolution of the systems, emitting gravitational waves at different frequencies, depending on the phase.
The best modelled sources are binary systems, typically Neutron Stars (NS), White Dwarfs and Black Holes (BH), orbiting each other. Fig. \ref{binary} shows the main phases of the evolution of the systems, emitting gravitational waves at different frequencies, depending on the phase.
\begin{figure}[h!]
\centering
\includegraphics[scale=1]{images/bin.png}
\caption[Phases of gravitational waves emission by a binary system]{The three phases of a BH-BH binary system emitting gravitational waves (amplitude vs time). \textbf{Inspiral phase}: the orbits shrink, velocity increases and frequency of the waves emitted increases as $f_{gw}=2f_{orbital}$. \textbf{Merging phase}: the objects merge and the signal is maximum. \textbf{Ring-down phase}: a new BH is formed and the signal emitted decreases in frequency as a damped sinusoid.}
\caption[Phases of gravitational waves emission by a binary system]{The three phases of a BH-BH binary system emitting gravitational waves (amplitude vs time)\cite{first}. \textbf{Inspiral phase}: the orbits shrink, velocity increases and frequency of the waves emitted increases as $f_{gw}=2f_{orbital}$. \textbf{Merging phase}: the objects merge and the signal is maximum. \textbf{Ring-down phase}: a new BH is formed and the signal emitted decreases in frequency as a damped sinusoid.}
\label{binary}
\end{figure}
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@@ -268,7 +269,7 @@ which gives a phase shift:
The higher is F, the higher is the effective length of the cavity and higher is the measureble phase shift.\\
\noindent
The first detection of gravitational waves happened on the 14th September 2015 and confirmed the Theory General Relativity, opening a new window on the Universe: among others, black holes have been observed thanks to their emission of gravitational waves, confirming the existence of these object, still mostly unknown \cite{first}. The detector responsible of the new discovery is based in the USA and it is one of the terrestrial interferometers currently in use for gravitational waves detection.
The first detection of gravitational waves happened on the 14th September 2015 and confirmed the Theory General Relativity, opening a new window on the Universe: the signal from a merger of two black holes have been observed thanks to the emission of gravitational waves, confirming the existence of these objects, still mostly unknown \cite{first}. The detector responsible of the new discovery is based in the USA and it is one of the terrestrial interferometers currently in use for gravitational waves detection.
%\section{LIGO}
%The ambition of this work is to give a contribution to the improvement of one of the interferometric detectors in use at present time, based in the USA: the Advanced Laser Interferometric Gravitational-wave Observatory (aLIGO).\\
@@ -44,8 +81,25 @@ Useful notations, constants and formulas go here.
\include{Ch.2}
\include{Ch.3}
\include{Ch.4}
%\include{Ch.5}
%
%\include{Ch.6}
%
%\include{Ch.7}
\appendix
\include{A}
\include{B}
\backmatter
\listoffigures
\listoftables
\begin{thebibliography}{}
\bibitem{wei} S. Weinberg \textit{Gravitation and Cosmology: principles and applications of the General Theory of Relativity}, John Wiley \& Sons, Inc., 1972
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@@ -61,14 +115,13 @@ Useful notations, constants and formulas go here.
\bibitem{abb} B. P. Abbott et al, \textit{GW150914: The Advanced LIGO Detectors in the Era of First Discoveries}, Phys. Rev. Lett. 116, 131102, 2016
\bibitem{mar} D. Martynov et al., \textit{The Sensitivity of the Advanced LIGO Detectors at the
Beginning of Gravitational Wave Astronomy}, ...
Beginning of Gravitational Wave Astronomy}
\bibitem{mat} F. Matichard et al, \textit{Seismic isolation of Advanced LIGO: Review of strategy, instrumentation and performance}, Class. Quantum Grav. 32 185003, 2015
\end{thebibliography}
\bibitem{lsc} K. Izumi, D. Sigg, \textit{Advanced LIGO: length sensing and control in a dual recycled interferometric gravitational wave antenna}, 2017 Class. Quantum Grav. 34 015001