CDM Framework Research Articles

Model marginalized constraints on neutrino properties from cosmology

We present robust, model-marginalized limits on both the total neutrino mass ($\sum m_\nu$) and abundance ($N_{\rm eff}$) to minimize the role of parameterizations, priors and models when extracting neutrino properties from cosmology. The cosmological observations we consider are CMB temperature fluctuation and polarization measurements, Supernovae Ia luminosity distances, BAO observations and determinations of the growth rate parameter from the Data Release 16 of the Sloan Digital Sky Survey IV. The degenerate neutrino mass spectrum (which implies $\sum m_\nu>0$) is weakly (moderately) preferred over the normal and inverted hierarchy possibilities, which imply the priors $\sum m_\nu>0.06$ and $\sum m_\nu>0.1$ eV respectively. Concerning the underlying cosmological model, the $\Lambda$CDM minimal scenario is almost always strongly preferred over the possible extensions explored here. The most constraining $95\%$ CL bound on the total neutrino mass in the $\Lambda$CDM+$\sum m_\nu$ picture is $\sum m_\nu< 0.087$ eV. The parameter $N_{\rm eff}$ is restricted to $3.08\pm 0.17$ ($68\%$ CL) in the $\Lambda$CDM+$N_{\rm eff}$ model. These limits barely change when considering the $\Lambda$CDM+$\sum m_\nu$+$N_{\rm eff}$ scenario. Given the robustness and the strong constraining power of the cosmological measurements employed here, the model-marginalized posteriors obtained considering a large spectra of non-minimal cosmologies are very close to the previous bounds, obtained within the $\Lambda$CDM framework in the degenerate neutrino mass spectrum. Future cosmological measurements may improve the current Bayesian evidence favouring the degenerate neutrino mass spectra, challenging therefore the consistency between cosmological neutrino mass bounds and oscillation neutrino measurements, and potentially suggesting a more complicated cosmological model and/or neutrino sector.

Revealing intrinsic flat ΛCDM biases with standardizable candles

Emerging high redshift cosmological probes, in particular quasars (QSOs), show a preference for larger matter densities, $\Omega_{m} \approx 1$, within the flat $\Lambda$CDM framework. Here, using the Risaliti-Lusso relation for standardizable QSOs, we demonstrate that the QSOs recover the \textit{same} Planck-$\Lambda$CDM Universe as Type Ia supernovae (SN), $\Omega_m \approx 0.3$ at lower redshifts $ 0 < z \lesssim 0.7$, before transitioning to an Einstein-de Sitter Universe ($\Omega_m =1$) at higher redshifts $z \gtrsim 1$. We illustrate the same trend, namely increasing $\Omega_{m}$ and decreasing $H_0$ with redshift, in SN but poor statistics prevent a definitive statement. We explain physically why the trend is expected in the flat $\Lambda$CDM cosmology, illustrate the intrinsic bias and non-Gaussian tails with mock Pantheon data, and identify a similar trend in BAO below $z=1$. Our results highlight an intrinsic bias in the flat $\Lambda$CDM Universe, whereby $\Omega_m$ increases, $H_0$ decreases and $S_8$ increases with effective redshift, thus providing a new perspective on $\Lambda$CDM tensions; even in a Planck-$\Lambda$CDM Universe the current tensions might have been expected.

Road-rail intermodality and the Clean Development Mechanism

The approval of methodologies involving the transportation sector confronts methodological concepts that hinder the eligibility of such projects as Clean Development Mechanism, mainly because it is a segment whose emissions come from mobile sources. The verification of additionality and monitoring of emissions, in principle, can be regarded as some of the key barriers to fit transportation sector projects into the CDM framework. This paper discusses these issues and examines, in particular, the road-rail intermodality. Since the partial replacement of cargo transport via trucks by wagon trains presents a great potential for mitigating emissions of greenhouse gases, this paper also analyzes the characteristics that a project involving road-rail intermodality must possess in order to be approved by the Executive Board of the United Nations Framework Convention on Climate Change. It also analyzes the main difficulties that such a project might face.

TightH0 constraint from galaxy redshift surveys: combining baryon acoustic oscillation measurements and Alcock–Paczynski test with a CMB prior

We report a tight Hubble constant constraint $67.78^{+1.21}_{-1.86}$ km s$^{-1}$ Mpc$^{-1}$ (2.26\% precision) derived from galaxy redshift surveys. We combine the BAO measurements from 6dFGS, the SDSS DR7 main galaxies, the BOSS DR12 galaxies, and eBOSS DR14 quasars, and also apply the tomographic Alcock-Paczynski (AP) method to the BOSS DR12 galaxies, to place constraints on $H_0$ in the spatially flat $\Lambda$CDM framework. Our result is fully consistent with the CMB constraints from Planck, but in $2.58\sigma$ tension with local measurements of Riess et al. 2016. Compared with the BAO alone constraint, the BAO+AP combined result reduces the error bar by 32%. This shows the strong power of the tomographic AP method in extracting cosmological information from galaxy redshift surveys.

EDGES result versus CMB and low-redshift constraints on ionization histories

We examine the results from the Experiment to Detect the Global Epoch of Reionization Signature (EDGES), which has recently claimed the detection of a strong absorption in the 21 cm hyperfine transition line of neutral hydrogen, at redshifts demarcating the early stages of star formation. More concretely, we study the compatibility of the shape of the EDGES absorption profile, centered at a redshift of $z \sim 17.2$, with measurements of the reionization optical depth, the Gunn-Peterson optical depth, and Lyman-$\alpha$ emission from star-forming galaxies, for a variety of possible reionization models within the standard $\Lambda$CDM framework (that is, a Universe with a cosmological constant and cold dark matter). When, conservatively, we only try to accommodate the location of the absorption dip, we identify a region in the parameter space of the astrophysical parameters that successfully explains all of the aforementioned observations. However, one of the most abnormal features of the EDGES measurement is the absorption amplitude, which is roughly a factor of two larger than the maximum allowed value in the $\Lambda$CDM framework. We point out that the simple considered astrophysical models that produce the largest absorption amplitudes are unable to explain the depth of the dip and of reproducing the observed shape of the absorption profile.

From light to baryonic mass: the effect of the stellar mass-to-light ratio on the Baryonic Tully–Fisher relation

In this paper we investigate the statistical properties of the Baryonic Tully-Fisher relation (BTFr) for a sample of 32 galaxies with accurate distances based on Cepheids and/or TRGB stars. We make use of homogeneously analysed photometry in 18 bands ranging from the FUV to 160 $\mu$m, allowing us to investigate the effect of the inferred stellar mass-to-light ratio $\Upsilon_{*}$ on the statistical properties of the BTFr. Stellar masses of our sample galaxies are derived with four different methods based on full SED-fitting, studies of stellar dynamics, near-infrared colours, and the assumption of the same $\Upsilon_{*}^{[3.6]}$ for all galaxies. In addition, we use high-quality, resolved HI kinematics to study the BTFr based on three kinematic measures: $W_{50}^{i}$ from the global HI profile, and $V_{max}$ and $V_{flat}$ from the rotation curve. We find the intrinsic perpendicular scatter, or tightness, of our BTFr to be $\sigma_{\perp} = 0.026 \pm 0.013$ dex, consistent with the intrinsic tightness of the 3.6 $\mu$m luminosity-based TFr. However, we find the slope of the BTFr to be $2.99 \pm 0.2$ instead of $3.7 \pm 0.1$ for the luminosity-based TFr at 3.6 $\mu$m. We use our BTFr to place important observational constraints on theoretical models of galaxy formation and evolution by making comparisons with theoretical predictions based on either the $\Lambda$CDM framework or modified Newtonian dynamics.

Briefing: River weirs – updated guide will help meet CDM and water framework directive requirements

Ciria has published River Weirs: Design, Maintenance, Modification and Removal to replace the Environment Agency's River Weirs Good Practice Guide of 2003. Although the previous guide was comprehensive, many lessons have been learned on the safety and operation of weirs since its publication. The water framework directive has also increased the emphasis on weir removal, lowering or modification to restore fish passage and natural geomorphological processes. In addition, interest in green energy has increased the use of weirs for hydropower generation. The new guide is aimed at all those with an interest in weirs and is freely available online. This briefing describes the functions of weirs and typical construction, potential impacts on safety and the environment, and what can be done to address shortfalls in performance. Finally, it highlights the need to raise awareness of the potential impacts of weirs among professionals and those responsible for weirs.

Effect of primordial non-Gaussianities on galaxy clusters scaling relations

Galaxy clusters are a valuable source of cosmological information. Their formation and evolution depends on the underlying cosmology and on the statistical nature of the primordial density fluctuations. In this work we investigate the impact of primordial non-gaussianities (PNG) on the scaling properties of galaxy clusters. We performed a series of cosmological hydrodynamic N-body simulations featuring adiabatic gas physics and different levels of non-Gaussian initial conditions within the $\Lambda$CDM framework. We focus on the T-M, S-M, Y-M and Yx-M scalings relating the total cluster mass with temperature, entropy and SZ cluster integrated pressure that reflect the thermodynamical state of the intra-cluster medium. Our results show that PNG have an impact on cluster scalings laws. The mass power-law indexes of the scalings are almost unaffected by the existence of PNG but the amplitude and redshift evolution of their normalizations are clearly affected. The effect is stronger for the evolution of the Y-M and Yx-M normalizations, which change by as much as 22% and 16% when $f_{NL}$ varies from -500 to 500, respectively. These results are consistent with the view that positive/negative $f_{NL}$ affect cluster profiles due to an increase/decrease of cluster concentrations. At low values of $f_{NL}$, as suggested by present Planck constraints on a scale invariant $f_{NL}$, the impact on the scalings normalizations is only a few percent, which is small when compared with the effect of additional gas physics and other cosmological effects such as dark energy. However if $f_{NL}$ is in fact a scale dependent parameter, PNG may have larger positive/negative amplitudes at clusters scales and therefore our results suggest that PNG should be taken into account when galaxy cluster data is used to infer cosmological parameters or to asses the constraining power of future cluster surveys.

CDM 20 years after

ABSTRACTIn year 1998, the seminal paper Research Innovation and Productivity: An Econometric Analysis at the Firm Level was published in this journal. The empirical framework, following on ideas in the research of Zvi Griliches at the NBER and commonly labeled CDM (the acronym of the three authors’ names, Crépon, Duguet and Mairesse) is one of the most influential contributions in recent literature on economics of innovation. The original CDM paper and papers inspired by its framework have received hundreds of citations in the empirical innovation literature. Whether directly linked or not to the CDM framework, the flow of studies improving on and enlarging the scope and methods of the empirical literature on R&D, innovation and productivity is continuing. Some of them, for example, focus on financing innovation, innovation and employment, innovation and trade, competition, or intellectual property; some adopt a managerial perspective, while others prefer an innovation system approach in a Schumpeterian tradition, etc. This introduction to the special issue of EINT surveys a collection of 12 papers on the CDM model by 25 authors from eight countries. The papers take stock of the evolution of research based on the original CDM model launched 20 years ago, linking it to the previous literature, and proposing developments and generalizations of it in various dimensions.

Family ownership: does it matter for funding and success of corporate innovations?

Using the Mannheim innovation panel, we investigate whether family firms have higher financial need and how this affects both innovation input and innovation outcomes such as firm or market novelties, or process innovation. Applying the CDM framework, we find that family firms are more likely to have a latent financial need for innovation, which means that they have innovation ideas which they have not implemented yet. We find that family firms have a significantly lower marginal innovation productivity in particular for innovations with radical character, i.e., market novelties. We conclude from this evidence that family firms have a comparative disadvantage in innovation projects that imply high risk and require high innovation capability.

The CDM framework: knowledge recombination from an evolutionary viewpoint

ABSTRACTSince Crepon, Duguet, and Mairesse published their ground-breaking article (‘Research, Innovation and Productivity: An Econometric Analysis at the Firm Level’, 1998), the CDM framework has known a large diffusion, despite being published in a non-indexed journal. The present study is an exploration of the spread and recombination of ‘knowledge’ in the ‘CDM universe’, comprising all papers in Scopus indexed journals citing CDM or/and CDM cited papers. We assess first the speed and range of diffusion of CDM and investigate next the ‘origins’ and further ‘genealogical’ make up of the knowledge recombinations within the CDM universe. We find that CDM is cited by a growing number of papers, which spread over a variety of fields, and that it compares very well with the most cited comparable articles in indexed journals in its domain of research. We further find that the CDM universe is mainly constituted of three large clusters and for each of them we are able to identify knowledge paths going from the CDM and earlier cited papers to the subsequent main citing papers. We intend to provide a detailed interpretation of these findings in future work.

Innovation Capabilities and Financing Constraints of Family Firms

Using the 2007 Mannheim innovation survey, we investigate whether family firms are more financially constrained than other firms and how this affects both innovation input as well as innovation outcomes such as market and firm novelties or process innovations. Based on the CDM framework, estimation of the recursive system of equations shows that family businesses are more likely to be constrained and have, on average, lower innovation input. Surprisingly, however, this does not reduce their innovation outcomes as, on average, family firms have the same level of innovation outcomes as nonfamily firms.

Dealing with Climate Change: Concerns and Options

Changes have occurred in the composition of greenhouse gases in the lower atmosphere during the last century primarily from the burning of fossil fuels and deforestation in tropical regions. Climate change is posing great threat to wildlife and protected areas by modifying habitats and increasing the prevalence of threats such as fire, pests and pathogens. Therefore, a climate change assessment is necessary to cope up with the adversities due to climate change. It has been suggested that forest action can cost effectively p rovide around 30% of the total effort needed in all sectors to meet climate mitigation strategies. Plantation programs can be used to create carbon credits to generate significant income for developing countries. The other most familiar ways to reduce GHG emissions are increasing energy efficiency and using alternative energy sources. In Indian context, the undervaluation of forests is causing immense losses to the forestry sector and overall economic system. The implementation of REDD+ and CDM framework could provide an opportunity to create and secure economic funds management, conservation and restoration of forests for mitigating climate change. The concept of Joint Forest Management and social forestry based on principals of community forestry has also gained a widespread significance in managing forests over the entire nation. The possibilities for mitigation in India also lie in the renewable energy sector along with industrial sector with improved energy efficiency. Integrated measures and effort at all international, national and regional are needed to fight against the changing climate.

Dark energy dependent test of general relativity at cosmological scales

The $\Lambda$CDM framework offers a remarkably good description of our universe with a very small number of free parameters, which can be determined with high accuracy from currently available data. However, this does not mean that the associated physical quantities, such as the curvature of the universe, have been directly measured. Similarly, general relativity is assumed, but not tested. Testing the relevance of general relativity for cosmology at the background level includes a verification of the relation between its energy contents and the curvature of space. Using an extended Newtonian formulation, we propose an approach where this relation can be tested. Using the recent measurements on cosmic microwave background, baryonic acoustic oscillations and the supernova Hubble diagram, we show that the prediction of general relativity is well verified in the framework of standard $\Lambda$CDM assumptions, i.e. an energy content only composed of matter and dark energy, in the form of a cosmological constant or equivalently a vacuum contribution. However, the actual equation of state of dark fluids cannot be directly obtained from cosmological observations. We found that relaxing the equation of state of dark energy opens a large region of possibilities, revealing a new type of degeneracy between the curvature and the total energy content of the universe.

Quadrant asymmetry in the angular distribution of cosmic microwave background in thePlancksatellite data

Some peculiar features found in the angular distribution of the cosmic microwave background (CMB) measured by the Wilkinson Microwave Anisotropy Probe (WMAP) deserve further investigation. Among these peculiar features, is the quadrant asymmetry, which is likely related to the north-south asymmetry. In this paper, we aim to extend the analysis of the quadrant asymmetry in the $\Lambda$CDM framework to the Planck foreground-cleaned maps, using the mask provided by Planck team. We compute the two-point correlation function (TPCF) from each quadrant of the Planck CMB sky maps, and compare the result with 1000 Monte Carlo (MC) simulations generated assuming the $\Lambda$CDM best-fit power spectrum. We detect the presence of an excess of power in the southeastern quadrant (SEQ) and a significant lack of power in the northeastern quadrant (NEQ) in the Planck data. Asymmetries between the SEQ and the other three quadrants (southwestern quadrant (SWQ), northwestern quadrant (NWQ), and NEQ) are each in disagreement with an isotropic sky at a 95\% confidence level. Furthermore, by rotating the Planck temperature sky map with respect to z direction, we showed the rotation angle where the TPCF of the SEQ has its maximal power. Our analysis of the Planck foreground-cleaned maps shows that there is an excess of power in the TPCF in the SEQ and a significant lack of power in the NEQ when compared with simulations. This asymmetry is anomalous when considering the $\Lambda$CDM framework .

Structure and substructure analysis of DAFT/FADA galaxy clusters in the [0.4–0.9] redshift range

We analyse the structures of all the clusters in the DAFT/FADA survey for which XMM-Newton and/or a sufficient number of galaxy redshifts in the cluster range is available, with the aim of detecting substructures and evidence for merging events. These properties are discussed in the framework of standard cold dark matter cosmology.XMM-Newton data were available for 32 clusters, for which we derive the X-ray luminosity and a global X-ray temperature for 25 of them. For 23 clusters we were able to fit the X-ray emissivity with a beta-model and subtract it to detect substructures in the X-ray gas. A dynamical analysis based on the SG method was applied to the clusters having at least 15 spectroscopic galaxy redshifts in the cluster range: 18 X-ray clusters and 11 clusters with no X-ray data. Only major substructures will be detected. Ten substructures were detected both in X-rays and by the SG method. Most of the substructures detected both in X-rays and with the SG method are probably at their first cluster pericentre approach and are relatively recent infalls. We also find hints of a decreasing X-ray gas density profile core radius with redshift. The percentage of mass included in substructures was found to be roughly constant with redshift with values of 5-15%, in agreement both with the general CDM framework and with the results of numerical simulations. Galaxies in substructures show the same general behaviour as regular cluster galaxies; however, in substructures, there is a deficiency of both late type and old stellar population galaxies. Late type galaxies with recent bursts of star formation seem to be missing in the substructures close to the bottom of the host cluster potential well. However, our sample would need to be increased to allow a more robust analysis.

Dark energy constraints after the new Planck data

The Planck collaboration has recently published maps of the Cosmic Microwave Background radiation with the highest precision. In the standard flat $\Lambda$CDM framework, Planck data show that the Hubble constant $H_0$ is in tension with that measured by the several direct probes on $H_0$. In this paper, we perform a global analysis from the current observational data in the general dark energy models and find that resolving this tension on $H_0$ requires the dark energy model with its equation of state (EoS) $w\neq-1$. Firstly, assuming the $w$ to be a constant, the Planck data favor $w < -1$ at about $2\,\sigma$ confidence level when combining with the supernovae "SNLS" compilation. And consequently the value derived on $H_0$, $H_0=71.3\pm2.0$ ${\rm km\,s^{-1}\,Mpc^{-1}}$ (68% C.L.), is consistent with that from direct $H_0$ probes. We then investigate the dark energy model with a time-evolving $w$, and obtain the 68% C.L. constraints $w_0=-0.81\pm0.19$ and $w_a=-1.9\pm1.1$ from the Planck data and the "SNLS" compilation. Current data still slightly favor the Quintom dark energy scenario with EoS across the cosmological constant boundary $w\equiv-1$.

Neutrinos and dark energy constraints from future galaxy surveys and CMB lensing information

We explore the possibility of obtaining better constraints from future astronomical data by means of the Fisher information matrix formalism. In particular, we consider how cosmic microwave background (CMB) lensing information can improve our parameter error estimation. We consider a massive neutrino scenario and a time-evolving dark energy equation of state in the $\Lambda$CDM framework. We use Planck satellite experimental specifications together with the future galaxy survey Euclid in our forecast. We found improvements in almost all studied parameters considering Planck alone when CMB lensing information is used. In this case, the improvement with respect to the constraints found without using CMB lensing is of 93% around the fiducial value for the neutrino parameter. The improvement on one of the dark energy parameter reaches 4.4%. When Euclid information is included in the analysis, the improvements on the neutrino parameter constraint is of approximately 128% around its fiducial value. The addition of Euclid information provides smaller errors on the dark energy parameters as well. For Euclid alone, the FoM is a factor of $\sim$ 29 higher than that from Planck alone even considering CMB lensing. Finally, the consideration of a nearly perfect CMB experiment showed that CMB lensing cannot be neglected specially in more precise future CMB experiments since it provided in our case a 6 times better FoM in respect to the unlensed CMB analysis .

Predictions for the CO emission of galaxies from a coupled simulation of galaxy formation and photon-dominated regions

We combine the galaxy formation model GALFORM with the Photon Dominated Region code UCL_PDR to study the emission from the rotational transitions of 12CO (CO) in galaxies from z=0 to z=6 in the Lambda CDM framework. GALFORM is used to predict the molecular (H2) and atomic hydrogen (HI) gas contents of galaxies using the pressure-based empirical star formation relation of Blitz & Rosolowsky. From the predicted H2 mass and the conditions in the interstellar medium, we estimate the CO emission in the rotational transitions 1-0 to 10-9 by applying the UCL_PDR model to each galaxy. We find that deviations from the Milky-Way CO-H2 conversion factor come mainly from variations in metallicity, and in the average gas and star formation rate surface densities. In the local universe, the model predicts a CO(1-0) luminosity function (LF), CO-to-total infrared (IR) luminosity ratios for multiple CO lines and a CO spectral line energy distribution (SLED) which are in good agreement with observations of luminous and ultra-luminous IR galaxies. At high redshifts, the predicted CO SLED of the brightest IR galaxies reproduces the shape and normalization of the observed CO SLED. The model predicts little evolution in the CO-to-IR luminosity ratio for different CO transitions, in good agreement with observations up to z~5. We use this new hybrid model to explore the potential of using colour selected samples of high-redshift star-forming galaxies to characterise the evolution of the cold gas mass in galaxies through observations with the Atacama Large Millimeter Array.

Stellar Populations of the Most Massive Galaxies

Within the hierarchical CDM framework, gas-poor mergers contribute substantially to the building of the most massive galaxies (Faber et al. 2007). We want to test this scenario by studying the fundamental plane (FP) and the stellar populations of the most massive galaxies. We investigate a well-defined sample of massive early-type galaxies at 0.1&lt;z&lt;0.4, identified from the SDSS database. Out of 42,000 possible targets in the SDSS database, we extracted 23 luminous early-type galaxies with bona fide high velocity dispersions of σ&gt;350 km s−1. These systems are located either in high or low-density environments and show a variety of small surface-brightness structure. Using archival HST/ACS images and Gemini/GMOS spectroscopy, we will explore the photometric and spectroscopic properties of these galaxies.