Publications (84)
Neutrinos and dark matter in galactic halos
Philippe Jetzer
One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves i…
Constraining decaying dark energy density models with the CMB temperature-redshift relation
Philippe Jetzer, Crescenzo Tortora
We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as , z being the redshift. These models lead to t…
Testing General Relativity with LISA including Spin Precession and Higher Harmonics in the Waveform
Cédric Huwyler, Antoine Klein, Philippe Jetzer
We compute the accuracy at which a LISA-like space-based gravitational wave detector will be able to observe deviations from General Relativity in the low frequency approximation.…
Effective-one-body Hamiltonian with next-to-leading order spin-spin coupling for two nonprecessing black holes with aligned spins
Simone Balmelli, Philippe Jetzer
The canonical Arnowitt-Deser-Misner (ADM) Hamiltonian with next-to-leading order spin-spin coupling [J. Steinhoff, S. Hergt, and G. Schäfer] is converted into the EOB formalism of…
Gravitational waves from spinning compact binaries in hyperbolic orbits
Lorenzo De Vittori, Achamveedu Gopakumar, Anuradha Gupta +1
Compact binaries in hyperbolic orbits are plausible gravitational wave (GW) sources for the upcoming and planned GW observatories. We develop an efficient prescription to compute p…
Dark matter and alternative recipes for the missing mass
Crescenzo Tortora, Philippe Jetzer, Nicola R. Napolitano
Within the standard cosmological scenario the Universe is found to be filled by obscure components (dark matter and dark energy) for ~95% of its energy budget. In particular, almos…
Effective-one-body Hamiltonian with next-to-leading order spin-spin coupling
Simone Balmelli, Philippe Jetzer
We propose a way of including the next-to-leading (NLO) order spin-spin coupling into an effective-one-body (EOB) Hamiltonian. This work extends [S. Balmelli and P. Jetzer, Phys. R…
Exploring the Foundations of the Universe with Space Tests of the Equivalence Principle
Baptiste Battelier, Joël Bergé, Andrea Bertoldi +34
We present the scientific motivation for future space tests of the equivalence principle, and in particular the universality of free fall, at the level or better. Two po…
Limits on compact halo objects as dark matter from gravitational microlensing
Philippe Jetzer
Microlensing started with the seminal paper by PaczyÅski in 1986, first with observations towards the Large Magellanic Cloud and the galactic bulge. Since then many other targets…
Substructures in lens galaxies: PG1115+080 and B1555+375, two fold configurations
Marco Miranda, Philippe Jetzer
We study the anomalous flux ratio which is observed in some four-image lens systems, where the source lies close to a fold caustic. In this case two of the images are close to the…
STE-QUEST -- Space Time Explorer and QUantum Equivalence principle Space Test: The 2022 medium-class mission concept
Naceur Gaaloul, Holger Ahlers, Leonardo Badurina +45
Space-borne quantum technologies, particularly those based on atom interferometry, are heralding a new era of strategic and robust space exploration. The unique conditions of space…
A Time Domain Waveform for Testing General Relativity
Cédric Huwyler, Edward K. Porter, Philippe Jetzer
Gravitational-wave parameter estimation is only as good as the theory the waveform generation models are based upon. It is therefore crucial to test General Relativity (GR) once da…
Prospects for Fundamental Physics with LISA
Enrico Barausse, Emanuele Berti, Thomas Hertog +318
In this paper, which is of programmatic rather than quantitative nature, we aim to further delineate and sharpen the future potential of the LISA mission in the area of fundamental…
Laser Interferometer Space Antenna
Pau Amaro-Seoane, Heather Audley, Stanislav Babak +81
Following the selection of The Gravitational Universe by ESA, and the successful flight of LISA Pathfinder, the LISA Consortium now proposes a 4 year mission in response to ESA's c…
Gravitational Wave Polarization Modes in Theories
H. Rizwana Kausar, Lionel Philippoz, Philippe Jetzer
Many studies have been carried out in the literature to evaluate the number of polarization modes of gravitational waves in modified theories, in particular in theories. In…
The Potential of Continuous, Local Atomic Clock Measurements for Earthquake Prediction and Volcanology
Mihai Bondarescu, Ruxandra Bondarescu, Philippe Jetzer +1
Modern optical atomic clocks along with the optical fiber technology currently being developed can measure the geoid, which is the equipotential surface that extends the mean sea l…
LISA Pathfinder
Michele Armano, Heather Audley, Jonathon Baird +75
Since the 2017 Nobel Prize in Physics was awarded for the observation of gravitational waves, it is fair to say that the epoch of gravitational wave astronomy (GWs) has begun. Howe…
Parameter estimation for coalescing massive binary black holes with LISA using the full 2-post-Newtonian gravitational waveform and spin-orbit precession
Antoine Klein, Philippe Jetzer, Mauro Sereno
With one exception, previous analyses of the measurement accuracy of gravitational wave experiments for comparable-mass binary systems have neglected either spin-precession effects…
Efficient prescription to search for linear gravitational wave memory from hyperbolic black hole encounters and its application to the NANOGrav 12.5-year dataset
Subhajit Dandapat, Abhimanyu Susobhanan, Lankeswar Dey +3
Burst with memory events are potential transient gravitational wave sources for the maturing pulsar timing array (PTA) efforts. We provide a computationally efficient prescription…
New Horizons for Fundamental Physics with LISA
K. G. Arun, Enis Belgacem, Robert Benkel +138
The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about the fundamental theory of nature at play in the extreme gravity regime, where the gravitatio…
Astro2020 Science White Paper: Cosmology with a Space-Based Gravitational Wave Observatory
Robert Caldwell, Mustafa Amin, Craig Hogan +8
There are two big questions cosmologists would like to answer -- How does the Universe work, and what are its origin and destiny? A long wavelength gravitational wave detector -- w…
Effects of Interplanetary Dust on the LISA drag-free Constellation
Massimo Cerdonio, Fabrizio De Marchi, Roberto De Pietri +5
The analysis of non-radiative sources of static or time-dependent gravitational fields in the Solar System is crucial to accurately estimate the free-fall orbits of the LISA space…
Waveform Modelling for the Laser Interferometer Space Antenna
LISA Consortium Waveform Working Group, Niayesh Afshordi, Sarp Akçay +144
LISA, the Laser Interferometer Space Antenna, will usher in a new era in gravitational-wave astronomy. As the first anticipated space-based gravitational-wave detector, it will exp…
Gravitational microlensing: a method for detecting halo dark matter
Philippe Jetzer
It has been shown by PaczyÅski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in…
Terrestrial Very-Long-Baseline Atom Interferometry: Summary of the Second Workshop
Adam Abdalla, Mahiro Abe, Sven Abend +307
This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024, build…
Pulse redshift of pulsar timing array signals for all possible gravitational wave polarizations in modified general relativity
Adrian Boîtier, Shubhanshu Tiwari, Lionel Philippoz +1
Pulsar timing arrays (PTA) have the promise to detect gravitational waves (GWs) from sources which are in a unique frequency range of 10^-9 - 10^-6 Hz. This in turn also provides a…
Fourier domain gravitational waveforms for precessing eccentric binaries
Antoine Klein, Yannick Boetzel, Achamveedu Gopakumar +2
We build two families of inspiral waveforms for precessing binaries on eccentric orbits in the Fourier domain. To achieve this, we use a small eccentricity expansion of the wavefor…
Search for hyperbolic encounters of compact objects in the third LIGO-Virgo-KAGRA observing run
Sophie Bini, Shubhanshu Tiwari, Yumeng Xu +6
Gravitational-wave (GW) observations provide unique information about compact objects. As detectors sensitivity increases, new astrophysical sources of GW could emerge. Close hyper…
Testing scalar-tensor theories and PPN parameters in Earth orbit
Andreas Schärer, Raymond Angélil, Ruxandra Bondarescu +2
We compute the PPN parameters and for general scalar-tensor theories in the Einstein frame, which we compare to the existing PPN formulation in the Jordan frame for alter…
Microlensing Implications for Halo Dark Matter
Philippe Jetzer, Eduard Masso
The most accurate way to get information on the mass of the MACHOs (Massive Astrophysical Compact Halo Objects) is to use the method of mass moments. For the microlensing events de…
The local dark sector. Probing gravitation's low-acceleration frontier and dark matter in the Solar System neighborhood
Joel Bergé, Laura Baudis, Philippe Brax +18
We speculate on the development and availability of new innovative propulsion techniques in the 2040s, that will allow us to fly a spacecraft outside the Solar System (at 150 AU an…
Geophysical applicability of atomic clocks: direct continental geoid mapping
Ruxandra Bondarescu, Mihai Bondarescu, György Hetényi +3
The geoid is the true physical figure of the Earth, a particular equipotential surface of the gravity field of the Earth that accounts for the effect of all subsurface density vari…
Solar system tests of the cosmological constant
Philippe Jetzer, Mauro Sereno
We discuss the influence of the cosmological constant on the gravitational equations of motion of bodies with arbitrary masses and eventually solve the two-body problem. Obser…
Microlensing towards LMC and M31
Philippe Jetzer, Sebastiano Calchi Novati
The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical de…
Prospects for Measuring Planetary Spin and Frame-Dragging in Spacecraft Timing Signals
Andreas Schärer, Ruxandra Bondarescu, Prasenjit Saha +3
Satellite tracking involves sending electromagnetic signals to Earth. Both the orbit of the spacecraft and the electromagnetic signals themselves are affected by the curvature of s…
Memory effect from spinning unbound binaries
Lorenzo De Vittori, Achamveedu Gopakumar, Anuradha Gupta +1
We present a recently developed prescription to obtain ready-to-use gravitational wave (GW) polarization states for spinning compact binaries on hyperbolic orbits. We include leadi…
Microlensing towards different Galactic targets
Lukas Grenacher, Philippe Jetzer, Marcus Strässle +1
We calculate the optical depth and the number of events due to gravitational microlensing towards the Galactic bulge, the spiral arm directions Scutum, Scutum, Norma…
ASYMPTOTIC BEHAVIOR OF COMPLEX SCALAR FIELDS IN A FRIEDMAN-LEMAITRE UNIVERSE
David Scialom, Philippe Jetzer
We study the coupled Einstein-Klein-Gordon equations for a complex scalar field with and without a quartic self-interaction in a curvatureless Friedman-Lema\^ı\-tre Universe. The…
Limits on decaying dark energy density models from the CMB temperature-redshift relation
Philippe Jetzer, Denis Puy, Monique Signore +1
The nature of the dark energy is still a mystery and several models have been proposed to explain it. Here we consider a phenomenological model for dark energy decay into photons a…
Microlensing in globular clusters: the first confirmed lens
Philippe Jetzer
Microlensing observations toward globular clusters could be very useful to probe their low mass star and brown dwarf content. Using the large set of microlensing events detected so…
Time evolution of the perturbations for a complex scalar field in Friedmann-Lemaitre universe
Philippe Jetzer, David Scialom
We study the time evolution of small classical perturbations in a gauge invariant way for a complex scalar field in the early zero curvature Friedmann-Lema\^ıtre universe. We, thu…
Low-frequency gravitational-wave science with eLISA/NGO
Pau Amaro-Seoane, Sofiane Aoudia, Stanislav Babak +27
We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early…
Power spectrum of gravitational waves from unbound compact binaries
Lorenzo De Vittori, Philippe Jetzer, Antoine Klein
Unbound interacting compact binaries emit gravitational radiation in a wide frequency range. Since short burst-like signals are expected in future detectors, such as LISA or advanc…
Analytic series expansion of the overlap reduction function for gravitational wave search with pulsar timing arrays
Adrian Boîtier, Shubhanshu Tiwari, Philippe Jetzer
In our previous paper \cite{PTA1} we derived a generic expression for the pulse redshift the main observable for the Pulsar Timing Array (PTA) experiment for detection of gravitati…
eLISA: Astrophysics and cosmology in the millihertz regime
Pau Amaro-Seoane, Sofiane Aoudia, Stanislav Babak +27
This document introduces the exciting and fundamentally new science and astronomy that the European New Gravitational Wave Observatory (NGO) mission (derived from the previous LISA…
Microlensing towards the LMC
Philippe Jetzer
The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical de…
Series expansion of the overlap reduction function for scalar and vector polarizations for gravitational wave search with pulsar timing arrays
Adrian Boîtier, Tanguy Giroud, Shubhanshu Tiwari +1
In our previous work \cite{PTA2} we calculated the overlap reduction function for the tensor polarization without employing the short wavelength approximation, this was done by obt…
On Gravitational Radiation in Quadratic Gravity
Joachim Näf, Philippe Jetzer
We investigate the gravitational radiation emitted by an isolated system for gravity theories with Lagrange density . As a formal result we obtain leading order co…
Low-frequency Gravitational Wave Detection via Double Optical Clocks in Space
Jianfeng Su, Qiang Wang, Qinghua Wang +1
We propose a Doppler tracking system for gravitational wave detection via Double Optical Clocks in Space (DOCS). In this configuration two spacecrafts (each containing an optical c…
Dark matter and gamma rays from the galactic halo
Philippe Jetzer
The nature of the dark matter in the halo of our Galaxy is still largely unknown. The microlensing events found so far towards the Large Magellanic Cloud suggest that at most about…
Microlensing implications for halo dark matter
Philippe Jetzer
The French collaboration EROS and the American-Australian collaboration MACHO have reported the observation of altogether 10 microlensing events by monitoring during several…
Solving post-Newtonian accurate Kepler Equation
Yannick Boetzel, Abhimanyu Susobhanan, Achamveedu Gopakumar +2
We provide an elegant way of solving analytically the third post-Newtonian (3PN) accurate Kepler equation, associated with the 3PN-accurate generalized quasi-Keplerian parametrizat…
The remains of a spinning, hyperbolic encounter
Lorenzo De Vittori, Achamveedu Gopakumar, Anuradha Gupta +1
We review a recently proposed approach to construct gravitational wave (GW) polarization states of unbound spinning compact binaries. Through this rather simple method, we are able…
On the Mass of the Dark Compact Halo Objects
Philippe Jetzer, Eduard Masso
Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring…
Josephson junctions and dark energy
Philippe Jetzer, Norbert Straumann
In a recent paper Beck and Mackey [astro-ph/0603397] argue that the argument we gave in our paper [Phys. Lett. B 606, 77 (2005)] to disprove their claim that dark energy can be dis…
Testing General Relativity and Alternative Theories of Gravity with Space-based Atomic Clocks and Atom Interferometers
Ruxandra Bondarescu, Andreas Schärer, Philippe Jetzer +3
The successful miniaturisation of extremely accurate atomic clocks and atom interferometers invites prospects for satellite missions to perform precision experiments. We discuss th…
Temperature and entropy profiles of nearby cooling flow clusters observed with XMM-Newton
Rocco Piffaretti, Philippe Jetzer, Jelle Kaastra +1
We investigate temperature and entropy profiles of 13 nearby cooling flow clusters observed with the EPIC cameras of XMM-Newton. When normalized and scaled by the virial radius the…
Gravitational wave energy spectrum of hyperbolic encounters
Lorenzo De Vittori, Philippe Jetzer, Antoine Klein
The emission of gravitational waves is studied for a system of massive objects interacting on hyperbolic orbits within the quadrupole approximation following the work of Capozziell…
On the 1/c Expansion of f(R) Gravity
Joachim Näf, Philippe Jetzer
We derive for applications to isolated systems - on the scale of the Solar System - the first relativistic terms in the expansion of the space time metric for metr…
Gravitational-wave amplitudes for compact binaries in eccentric orbits at the third post-Newtonian order: Memory contributions
Michael Ebersold, Yannick Boetzel, Guillaume Faye +3
We compute the non-linear memory contributions to the gravitational-wave amplitudes for compact binaries in eccentric orbits at the third post-Newtonian (3PN) order in general rela…
Aspherical galaxy clusters: effects on cluster masses and gas mass fractions
Rocco Piffaretti, Philippe Jetzer, Sabine Schindler
We present an investigation of the effects of asphericity on the estimates of total mass and gas mass fraction in galaxy clusters from X-ray observations. We model the aspherical s…
Binary black hole mergers in AGN accretion discs: gravitational wave rate density estimates
Matthias Gröbner, Wako Ishibashi, Shubhanshu Tiwari +2
The majority of gravitational wave (GW) events detected so far by LIGO/Virgo originate from binary black hole (BBH) mergers. Among the different binary evolution paths, the merger…
Gravitational microlensing by the dark halo of M31
Philippe Jetzer
It has been shown by PaczyÅski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in…
Gravitational wave polarization from combined Earth-space detectors
Lionel Philippoz, Adrian Boîtier, Philippe Jetzer
In this paper, we investigate the sensitivity to additional gravitational wave polarization modes of future detectors. We first look at the upcoming Einstein Telescope and its comb…
On the Stability of Real Scalar Boson Stars
Philippe Jetzer, David Scialom
We discuss spherically symmetric static solutions of the Einstein-Klein-Gordon equations for a real scalar field with a mass and a quartic self-interaction term. As for the massles…
Has Dark Energy really been discovered in the Lab?
Philippe Jetzer, Norbert Straumann
We show that Dark Energy contributions can not be determined from noise measurements of Josephson junctions, as was recently suggested in a paper by C. Beck and M.C. Mackey.
Gravitational microlensing by the halo of the Andromeda galaxy
Philippe Jetzer
It has been shown by PaczyÅski that gravitational microlensing is a useful method to detect brown dwarfs in the dark halo of our galaxy. At present several experiments are carried…
Dark Matter distribution in the Milky Way: microlensing and dynamical constraints
Fabio Iocco, Miguel Pato, Gianfranco Bertone +1
We show that current microlensing and dynamical observations of the Galaxy permit to set interesting constraints on the Dark Matter local density and profile slope towards the gala…
Quantum Tests of the Einstein Equivalence Principle with the STE-QUEST Space Mission
Brett Altschul, Quentin G. Bailey, Luc Blanchet +20
We present in detail the scientific objectives in fundamental physics of the Space-Time Explorer and QUantum Equivalence Space Test (STE-QUEST) space mission. STE-QUEST was pre-sel…
Quadrupolar power radiation by a binary system in a hyperbolic encounter on de Sitter background
Michael Blanc, Philippe Jetzer, Shubhanshu Tiwari
The present cosmological model and the surveys favor the universe with a small but positive cosmological constant , which accounts for dark energy and causes an exponential exp…
Spacecraft Clocks and Relativity: Prospects for Future Satellite Missions
Raymond Angélil, Prasenjit Saha, Ruxandra Bondarescu +3
The successful miniaturization of extremely accurate atomic clocks invites prospects for satellite missions to perform precise timing experiments. This will allow effects predicted…
Spin effects in the phasing of gravitational waves from binaries on eccentric orbits
Antoine Klein, Philippe Jetzer
We compute here the spin-orbit and spin-spin couplings needed for an accurate computation of the phasing of gravitational waves emitted by comparable-mass binaries on eccentric orb…
A note on the gravitational wave energy spectrum of parabolic and hyperbolic encounters
Matthias Gröbner, Philippe Jetzer, Maria Haney +2
The first calculation of the frequency spectrum of gravitational wave mass quadrupole radiation for binaries on hyperbolic orbits was performed in arXiv:1207.5359. Some shortcoming…
Gravitational microlensing research
Philippe Jetzer
One of the most important problems in astrophysics concerns the nature of the dark matter in galactic halos, whose presence is implied mainly by the observed flat rotation curves i…
Cold Atoms in Space: Community Workshop Summary and Proposed Road-Map
Ivan Alonso, Cristiano Alpigiani, Brett Altschul +246
We summarize the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportu…
Characterisation of the Bedretto Underground Site for Fundamental Physics Experiments
Björn Penning, Nicolas Angelides, Laura Baudis +33
Underground laboratories provide the ultra-low background and low-vibration environments essential for rare-event searches, gravitational-wave detection, and quantum-sensing techno…
Microlensing events from galactic globular clusters
Philippe Jetzer
We present an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are loca…
Bending angle of light in equatorial plane of Kerr-Sen Black Hole
Rashmi Uniyal, Hemwati Nandan, Philippe Jetzer
We study the gravitational lensing by a Kerr-Sen Black Hole arising in heterotic string theory. A closed form expression for the bending angle of light in equatorial plane of Kerr-…
Constraints from the CMB temperature and other common observational data-sets on variable dark energy density models
Philippe Jetzer, Crescenzo Tortora
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline…
Galactic globular clusters contribution to microlensing events?
Fabiana De Luca, Philippe Jetzer
In this note we perform an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark le…
Atomic clocks as a tool to monitor vertical surface motion
Ruxandra Bondarescu, Andreas Schärer, Andrew Lundgren +4
Atomic clock technology is advancing rapidly, now reaching stabilities of , which corresponds to resolving cm in equivalent geoid height over an integratio…
LISA Pathfinder Platform Stability and Drag-free Performance
Michele Armano, Heather Audley, Jonathon Baird +75
The science operations of the LISA Pathfinder mission has demonstrated the feasibility of sub-femto-g free-fall of macroscopic test masses necessary to build a LISA-like gravitatio…
Supermassive Black Hole Tests of General Relativity with eLISA
Cédric Huwyler, Edward K. Porter, Philippe Jetzer
Motivated by the parameterized post-Einsteinian (ppE) scheme devised by Yunes and Pretorius, which introduces corrections to the post-Newtonian coefficients of the frequency domain…
LISA Definition Study Report
Monica Colpi, Karsten Danzmann, Martin Hewitson +108
The Laser Interferometer Space Antenna (LISA) is the first scientific endeavour to detect and study gravitational waves from space. LISA will survey the sky for Gravitational Waves…