Distinguishing Between Void Models and Dark Energy with Cosmic Parallax and Redshift Drift (2009)
Quartin, Miguel, Amendola, Luca
Two recently proposed techniques, involving the measurement of the cosmic parallax and redshift drift, provide novel ways of directing probing (over a time-span of several years) the background...
Reconstruction of the bubble nucleating potential (2009)
Luca Amendola, Carlo Baccigalupi, Rostislav Konoplich, Franco Occhionero, Sergei Rubin
We calculate analytically the bubble nucleation rate in a model of rst order in ation which is able to produce large scale structure. The computation includes the rst-order departure from the...
Cosmological constraints on the Hu-Sawicki modified gravity scenario (2009)
Martinelli, Matteo, Melchiorri, Alessandro, Amendola, Luca
In this paper we place new constraints on a f(R) modified gravity model recently proposed by Hu and Sawicki. After checking that the Hu and Sawicki model produces a viable cosmology, i.e. a matter...
Cosmic Parallax as a probe of late time anisotropic expansion (2009)
Quercellini, Claudia, Cabella, Paolo, Amendola, Luca, Quartin, Miguel, Balbi, Amedeo
Cosmic parallax is the change of angular separation between pair of sources at cosmological distances induced by an anisotropic expansion. An accurate astrometric experiment like Gaia could observe...
Findings of the Joint Dark Energy Mission Figure of Merit Science Working Group (2009)
Albrecht, Andreas, Amendola, Luca, Bernstein, Gary, Clowe, Douglas, Eisenstein, Daniel, Guzzo, Luigi, ...
These are the findings of the Joint Dark Energy Mission (JDEM) Figure of Merit (FoM) Science Working Group (SWG), the FoMSWG. JDEM is a space mission planned by NASA and the DOE for launch in the...
Deconstructing Baryon Acoustic Oscillations: A Comparison of Methods (2008)
Rassat, Anais, Amara, Adam, Amendola, Luca, Castander, Francisco J., Kitching, Thomas, Kunz, Martin, ...
The Baryon Acoustic Oscillations (BAOs) or baryon wiggles which are present in the galaxy power spectrum at scales 100-150Mpc/h are powerful features with which to constrain cosmology. The potential...
Quercellini, Claudia, Quartin, Miguel, Amendola, Luca
Refined astrometry measurements allow us to detect large-scale deviations from isotropy through real-time observations of changes in the angular separation between sources at cosmic distances. This...
Mapping the galactic gravitational potential with peculiar acceleration (2008)
Quercellini, Claudia, Amendola, Luca, Balbi, Amedeo
It has been suggested recently that the change in cosmological redshift (the Sandage test of expansion) could be observed in the next generation of large telescopes and ultra-stable spectrographs. In...
Dark Energy Phenomenology (2008)
Kunz, Martin, Amendola, Luca, Sapone, Domenico
We discuss the phenomenology of the dark energy in first order perturbation theory, demonstrating that the dark energy cannot be fully constrained unless the dark matter is found, and that there are...
Mimicking general relativity in the solar system (2008)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
In order for a modified gravity model to be a candidate for cosmological dark energy it has to pass stringent local gravity experiments. We find that a Brans-Dicke (BD) theory with well-defined...
The Stochastic Gravitational Background From Inflationary Phase Transitions (2007)
Carlo Baccigalupi, Luca Amendola, Pierluigi Fortini, Franco Occhionero
We consider true vacuum bubbles generated in a first order phase transition occurring during the slow rolling era of a two field inflation: it is known that gravitational waves are produced by the...
Constraining the growth factor with baryon oscillations (2007)
Sapone, Domenico, Amendola, Luca
The growth factor of linear fluctuations is probably one of the least known quantity in observational cosmology. Here we discuss the constraints that baryon oscillations in galaxy power spectra from...
Amendola, Luca, Quercellini, Claudia, Balbi, Amedeo
It has been proposed recently to observe the change in cosmological redshift of distant galaxies or quasars with the next generation of large telescope and ultra-stable spectrographs (the so-called...
Observational constraints on the linear fluctuation growth rate (2007)
Di Porto, Cinzia, Amendola, Luca
Several experiments in the near future will test dark energy through its effects on the linear growth of matter perturbations. It is therefore important to find simple and at the same time general...
Amendola, Luca, Baldi, Marco, Wetterich, Christof
We investigate quintessence cosmologies with a matter component consisting of particles with an increasing mass. While negligible in early cosmology, the appearance of a growing matter component has...
Amendola, Luca, Tsujikawa, Shinji
We identify the class of f(R) dark energy models which have a viable cosmology, i.e. a matter dominated epoch followed by a late-time acceleration. The deviation from a LambdaCDM model (f=R-Lambda)...
Solar System Constraints on Gauss-Bonnet Mediated Dark Energy (2007)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Although the Gauss-Bonnet term is a topological invariant for general relativity, it couples naturally to a quintessence scalar field, modifying gravity at solar system scales. We determine the solar...
Measuring the dark side (with weak lensing) (2007)
Amendola, Luca, Kunz, Martin, Sapone, Domenico
We introduce a convenient parametrization of dark energy models that is general enough to include several modified gravity models and generalized forms of dark energy. In particular we take into...
Solar System Constraints on Gauss-Bonnet Mediated Dark Energy (2007)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Although the Gauss-Bonnet term is a topological invariant for general relativity, it couples naturally to a quintessence scalar field, modifying gravity at solar system scales. We determine the solar...
Conditions for the cosmological viability of f(R) dark energy models (2006)
Amendola, Luca, Gannouji, Radouane, Polarski, David, Tsujikawa, Shinji
We derive the conditions under which dark energy models whose Lagrangian densities f are written in terms of the Ricci scalar R are cosmologically viable. We show that the cosmological behavior of...
SNLS data are consistent with acceleration at z=3 (2006)
Amendola, Luca, Gasperini, M., Piazza, Federico
We point out that the Type Ia supernovae in the SNLS dataset are consistent with an early beginning of the cosmic acceleration if dark energy interacts strongly with dark matter. We find that the...
Challenges for scaling cosmologies (2006)
Amendola, Luca, Quartin, Miguel, Tsujikawa, Shinji, Waga, Ioav
A cosmological model that aims at solving the coincidence problem should show that dark energy and dark matter follow the same scaling solution from some time onward. At the same time, the model...
Power-laws f(R) theories are cosmologically unacceptable (2006)
Amendola, Luca, Polarski, David, Tsujikawa, Shinji
In a recent paper [1] (PRL 98,131302,2007) we have shown that f(R)=R + mu R^{n} modified gravity dark energy models are not cosmologically viable because during the matter era that precedes the...
Are f(R) dark energy models cosmologically viable ? (2006)
Amendola, Luca, Polarski, David, Tsujikawa, Shinji
All $f(R)$ modified gravity theories are conformally identical to models of quintessence in which matter is coupled to dark energy with a strong coupling. This coupling induces a cosmological...
Constraints on Gauss-Bonnet Gravity in Dark Energy Cosmologies (2005)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Accelerating four dimensional cosmologies, whose dark energy component includes the general contribution from second order gravity terms, are investigated. In particular the Gauss-Bonnet invariant,...
Dark Matter from an ultra-light pseudo-Goldsone-boson (2005)
Amendola, Luca, Barbieri, Riccardo
Dark Matter (DM) and Dark Energy (DE) can be both described in terms of ultra-light Pseudo-Goldstone-Bosons (PGB) with masses m_{DM} ~ 10^{-23}eV and m_{DE}
Observational Constraints on Silent Quartessence (2005)
Amendola, Luca, Waga, Ioav, Finelli, Fabio
We derive new constraints set by SNIa experiments (`gold' data sample of Riess et al.), X-ray galaxy cluster data (Allen et al. Chandra measurements of the X-ray gas mass fraction in 26 clusters),...
Constraints on Gauss-Bonnet Gravity in Dark Energy Cosmologies (2005)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Models with a scalar field coupled to the Gauss-Bonnet Lagrangian appear naturally from Kaluza-Klein compactifications of pure higher-dimensional gravity. We study linear, cosmological perturbations...
Phantom damping of matter perturbations (2005)
Amendola, Luca, Tsujikawa, Shinji, Sami, M.
Cosmological scaling solutions are particularly important in solving the coincidence problem of dark energy. We derive the equations of sub-Hubble linear matter perturbations for a general...
Constraints on Gauss-Bonnet Gravity in Dark Energy Cosmologies (2005)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Accelerating four dimensional cosmologies, whose dark energy component includes the general contribution from second order gravity terms, are investigated. In particular the Gauss-Bonnet invariant,...
Constraints on Gauss-Bonnet Gravity in Dark Energy Cosmologies (2005)
Amendola, Luca, Charmousis, Christos, Davis, Stephen C.
Accelerating four dimensional cosmologies, whose dark energy component includes the general contribution from second order gravity terms, are investigated. In particular the Gauss-Bonnet invariant,...
On the Effects due to a Decaying Cosmological Fluctuation (2004)
Amendola, Luca, Finelli, Fabio
We present the initial conditions for a decaying cosmological perturbation and study its signatures in the CMB anisotropies and matter power spectra. An adiabatic decaying mode in presence of...
Supernovae type Ia data favour coupled phantom energy (2004)
Majerotto, Elisabetta, Sapone, Domenico, Amendola, Luca
We estimate the constraints that the recent high-redshift sample of supernovae type Ia put on a phenomenological interaction between dark energy and dark matter. The interaction can be interpreted as...
Phantom energy mediates a long-range repulsive force (2004)
Scalar field models with non-standard kinetic terms have been proposed in the context of k-inflation, of Born-Infeld lagrangians, of phantom energy and, more in general, of low-energy string theory....
Testing for double inflation with WMAP (2004)
Parkinson, David, Tsujikawa, Shinji, Bassett, Bruce A., Amendola, Luca
With the WMAP data we can now begin to test realistic models of inflation involving multiple scalar fields. These naturally lead to correlated adiabatic and isocurvature (entropy) perturbations with...
Fitting Type Ia supernovae with coupled dark energy (2004)
Amendola, Luca, Gasperini, Maurizio, Piazza, Federico
We discuss the possible consistency of the recently discovered Type Ia supernovae at z>1 with models in which dark energy is strongly coupled to a significant fraction of dark matter, and in which an...
Constraints on perfect fluid and scalar field dark energy models from future redshift surveys (2004)
Amendola, Luca, Quercellini, Claudia, Giallongo, Emanuele
We discuss the constraints that future photometric and spectroscopic redshift surveys can put on dark energy through the baryon oscillations of the power spectrum. We model the dark energy either...
Skewness as a test of the equivalence principle (2004)
Amendola, Luca, Quercellini, Claudia
The skewness of the large scale distribution of matter has long been known to be a probe of gravitational clustering. Here we show that the skewness is also a probe of violation of the equivalence...
Linear and non-linear perturbations in dark energy models (2003)
I review the linear and second-order perturbation theory in dark energy models with explicit interaction to matter in view of applications to N-body simulations and non-linear phenomena. Several new...
N-body simulations for coupled dark energy: halo mass function and density profiles (2003)
Maccio', Andrea V., Quercellini, Claudia, Mainini, Roberto, Amendola, Luca, Bonometto, Silvio A.
We present the results of a series of N-body simulations in cosmologies where dark matter (DM) is coupled to dark energy (DE), so easing the cosmic coincidence problem. The dark-dark coupling...
Tracking and coupled dark energy as seen by WMAP (2003)
Amendola, Luca, Quercellini, Claudia
The satellite experiment WMAP has produced for the first time a high-coverage, high resolution survey of the microwave sky, releasing publicly available data that are likely to remain unrivalled for...
The nature of dark energy (2002)
Amendola,Luca, Quercellini,Claudia, Tocchini-Valentini,Domenico, Pasqui,Alessandro
According to a variety of cosmological observations at small and large redshifts, the universe is composed by a large fraction of a weakly clustered component with negative pressure, called dark...
Most models of dark energy predict the beginning of the accelerated epoch at z
Perturbations growth and bias during acceleration (2002)
Amendola, Luca, Tocchini-Valentini, Domenico
In most models of dark energy the structure formation stops when the accelerated expansion begins. In contrast, we show that the coupling of dark energy to dark matter may induce the growth of...
Amendola, Luca, Quercellini, Claudia, Tocchini-Valentini, Domenico, Pasqui, Alessandro
It is well-known that even high quality cosmic microwave background (CMB) observations are not sufficient on their own to determine the equation of state of the dark energy, due to the effect of the...
Baryon bias and structure formation in an accelerating universe (2001)
Amendola, Luca, Tocchini-Valentini, Domenico
In most models of dark energy the structure formation stops when the accelerated expansion begins. In contrast, we show that the coupling of dark energy to dark matter may induce the growth of...
Tocchini-Valentini, Domenico, Amendola, Luca
We show that all cosmological models with an accelerated stationary global attractor reduce asymptotically to a dark energy field with an exponential potential coupled linearly to a perfect fluid...
The estimation of cosmological parameters from cosmic microwave experiments has almost always been performed assuming gaussian data. In this paper the sensitivity of the parameter estimation to...
Correlated perturbations from inflation and the cosmic microwave background (2001)
Amendola, Luca, Gordon, Christopher, Wands, David, Sasaki, Misao
We compare the latest cosmic microwave background data with theoretical predictions including correlated adiabatic and CDM isocurvature perturbations with a simple power-law dependence. We find that...
Stationary dark energy: the present universe as a global attractor (2000)
Amendola, Luca, Tocchini-Valentini, Domenico
We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology...
Giovi, Fabio, Occhionero, Franco, Amendola, Luca
We calculate analytically and numerically the Dyer-Roeder distance in perfect fluid quintessence models and give an accurate fit to the numerical solutions for all the values of the density parameter...
Dark energy and the Boomerang data (2000)
The recent high-quality Boomerang data allow to test many competing cosmological models. Here I present a seven-parameter likelihood analysis of dark energy models with exponential potential and...
Il cielo infinito, Luca Amendola. . - Milano. NALUAF000464, Sperling & Kupfer. NAEDAF004701, 2000.
A new component of the cosmic medium, a light scalar field or ''quintessence '', has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is...
Time variability of the gravitational constant and Type Ia supernovae (1999)
Amendola, Luca, Corasaniti, Stefano, Occhionero, Franco
We investigate to which extent a time variation of the gravitational constant or other fundamental constants affects the best fit of the Hubble diagram of type Ia supernovae. In particular, we show...
Perturbations in a coupled scalar field cosmology (1999)
I analyze the density perturbations in a cosmological model with a scalar field coupled to ordinary matter, such as one obtains in string theory and in conformally transformed scalar-tensor theories....
The power spectrum of the Lyman-alpha clouds (1999)
Amendola, Luca, Savaglio, Sandra
We investigate the clustering properties of 13 QSO lines of sight in flat space, with average redshifts from z~2 to 4. We estimate the 1-D power spectrum and the integral density of neighbours, and...
Scaling solutions in general non-minimal coupling theories (1999)
A class of generalized non-minimal coupling theories is investigated, in search of scaling attractors able to provide an accelerated expansion at the present time. Solutions are found in the strong...
The scale of homogeneity in the Las Campanas Redshift Survey (1999)
Amendola, Luca, Palladino, Emilia
We analyse the Las Campanas Redshift Survey using the integrated conditional density (or density of neighbors) in volume-limited subsamples up to unprecedented scales (200 Mpc/$h$) in order to...
Weak Gravitational Lensing by Voids (1998)
Amendola, Luca, Frieman, Joshua A., Waga, Ioav
We consider the prospects for detecting weak gravitational lensing by underdensities (voids) in the large-scale matter distribution. We derive the basic expressions for magnification and distortion...
Non-Gaussian Chi-squared method with the multivariate Edgeworth expansion (1998)
I present here a generalization of the maximum likelihood method and the $\chi^2$ method to the cases in which the data are {\it not} assumed to be Gaussian distributed. The method, based on the...
Stochastic gravitational background from inflationary phase transitions (1997)
Baccigalupi, Carlo, Amendola, Luca, Fortini, Pierluigi, Occhionero, Franco
We consider true vacuum bubbles generated in a first order phase transition occurring during the slow rolling era of a two field inflation: it is known that gravitational waves are produced by the...
Reconstruction of the bubble nucleating potential (1996)
Amendola, Luca, Baccigalupi, Carlo, Konoplich, Rostislav, Occhionero, Franco, Rubin, Sergei
We calculate analytically the bubble nucleation rate in a model of first order inflation which is able to produce large scale structure. The computation includes the first-order departure from the...
Reconciling inflation with openness (1996)
Amendola, Luca, Baccigalupi, Carlo, Occhionero, Franco
It is already understood that the increasing observational evidence for an open Universe can be reconciled with inflation if our horizon is contained inside one single huge bubble nucleated during...
Anisotropic Inflation from Extra Dimensions (1995)
Litterio, Marco, Sokołowski, Leszek M., Golda, Zdzisław A., Amendola, Luca, Dyrek, Andrzej
Vacuum multidimensional cosmological models with internal spaces being compact $n$-dimensional Lie group manifolds are considered. Products of 3-spheres and $SU(3)$ manifold (a novelty in cosmology)...
Reconciling Inflation with Openness (1995)
Amendola, Luca, Baccigalupi, Carlo, Occhionero, Franco
It is already understood that the increasing observational evidence for an open Universe may be reconciled with inflation if our horizon is contained inside one single huge bubble nucleated during...
The power spectrum in a strongly inhomogeneous Universe (1995)
Labini, Francesco Sylos, Amendola, Luca
A crucial issue in cosmology is the determination of the fluctuation power spectrum.The standard picture of the matter clustering, the Cold Dark Matter model (and its variant), assumes that,on scales...
Non-Gaussian Likelihood Function (1995)
We generalize the maximum likelihood method to non-Gaussian distribution functions by means of the multivariate Edgeworth expansion. We stress the potential interest of this technique in all those...
String Cosmology and Inflation (1995)
Angelantonj, Carlo, Amendola, Luca, Litterio, Marco, Occhionero, Franco
Following a suggestion by Gasperini and Veneziano, that String Cosmology can be reconciled with Inflation and, hence, with the Standard Big Bang, we display an analytical solution which possesses...
Non-Gaussian statistics of pencil beam surveys (1994)
We study the effect of the non-Gaussian clustering of galaxies on the statistics of pencil beam surveys. We find that the higher order moments of the galaxy distribution play an important role in the...
Large-Scale Clustering in Bubble Models (1993)
Amendola, Luca, Borgani, Stefano
We analyze the statistical properties of bubble models for the large-scale distribution of galaxies. To this aim, we realize static simulations, in which galaxies are mostly randomly arranged in the...
Inflationary Attractors and Perturbation Spectra in Generally Coupled Gravity (1993)
Amendola, Luca, Bellisai, Diego, Occhionero, Franco, Observatory, Rome Astronomical
A generic outcome of theories with scalar-tensor coupling is the existence of inflationary attractors, either power-law or de Sitter. The fluctuations arising during this phase are Gaussian and their...
Cosmology with Nonminimal Derivative Couplings (1993)
We study a theory which generalizes the nonminimal coupling of matter to gravity by including derivative couplings. This leads to several interesting new dynamical phenomena in cosmology. In...
Stability of Compactiflcation During Inflation FERMILAB-Pub-90/47-A (1990)
Luca Amendola, Edward W. Kolb, Marco Litterio, Franco Occhionero
The possibility that inflation may trigger an instability in compactification of extra spatial dimensions is considered. In old, new, or extended inflation, the false vacuum energy results in a...