Impact of theoretical priors in cosmological analyses: the case of single field quintessence

Article / Letter to editorLeids Instituut Onderzoek Natuurkund

Itinerari nel sacro. L'esperienza religiosa giapponese

Il libro esamina le concezioni che fondano la tradizione religiosa giapponese attraverso i dati della ricerca sul campo svolta nei villaggi di alcune zone del Giappone e nelle comunità di asceti delle montagne sacre nella regione del Kansai. Lo studio mette in luce la complessità del discorso sul divino, nell'intreccio delle tradizioni Shinto, Buddhista e Daoista, la costruzione narrativa dell’ordine del mondo; i ritmi del tempo sacro scanditi dai riti della coltivazione del riso; gli immaginari della morte, il paradiso degli antenati e gli inferni degli spiriti inquieti, e la ricerca dell’immortalità. Lo studio si conclude con l'analisi delle forme dell'autorità religiosa tradizionale e la loro interazione con le tendenze di devianza e di rinnovamento

La reinvenzione della memoria nel discorso religioso del Giappone contemporaneo

L'articolo si incentra sull'analisi delle visioni escatologiche e delle strategie di salvezza proclamate dai movimenti di rinnovamento religioso emersi nel Giappone contemporaneo, le cosiddette “Nuove Nuove Religioni”, shin shinshukyo. Viene messo in luce come questi esprimano tendenze decisamente innovative, che possono essere viste come la manifestazione locale di ben definite tendenze spirituali globali che iniziano a evidenziarsi anche in Occidente a partire dagli anni Ottanta del secolo scorso. I loro messaggi di salvezza utilizzano nozioni e vocabolario buddhisti, ma con grande libertà ideologica includono nel proprio apparato simbolico idee, figure divine e pratiche rituali tratte dalle più diverse tradizioni sacre. A differenza dei movimenti religiosi di carattere nazionalista e integralista (sia shinto sia buddhisti) che hanno fondato e alimentato il mito identitario del Giappone anteguerra, questi movimenti rivelano una tendenza ad accettare la complessità, a farne propria la logica, a accogliere e rielaborare forme 'altre' di fede attraverso dei processi semiotici che richiamano l'ermeneutica esoterica medioevale fondata sulla dottrina dello honji suijaku (natura originaria-manifestazione). La rinascita dell'esoterismo è infatti una delle novità più significative del discorso religioso contemporaneo. Lo logica dei linguaggi virtuali dei media è intrinseca a questi nuovi movimenti: essi si esprimono negli ipertesti, nelle immagini e nella musica, nei grandi eventi spettacolari, utilizzando a fondo le tecniche di persuasione pubblicitaria, per proporre un'esperienza spirituale efficace, tesa a esaltare e gratificare l'ego, in sintonia con gli immaginari mediatici e i valori della cultura metropolitana del capitalismo della tarda modernità

Impact of theoretical priors in cosmological analyses: the case of single field quintessence

Theoretical Physic

Priors on the effective Dark Energy equation of state in scalar-tensor theories

archiveprefix: arXiv primaryclass: astro-ph.CO slaccitation: %%CITATION = ARXIV:1703.05297;%%archiveprefix: arXiv primaryclass: astro-ph.CO slaccitation: %%CITATION = ARXIV:1703.05297;%%archiveprefix: arXiv primaryclass: astro-ph.CO slaccitation: %%CITATION = ARXIV:1703.05297;%%MR is supported by U.S. Department of Energy Contract No. DE-FG02-13ER41958. PB is supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, California Institute of Technology, administered by Universities Space Research Association under contract with NASA. AS acknowledges support from the NWO and the Dutch Ministry of Education, Culture and Science (OCW), and also from the D-ITP consortium, a program of the NWO that is funded by the OCW. The work of LP is supported by the Natural Sciences and Engineering Research Council of Canada (NSERC)

Detecting dark energy fluctuations with gravitational waves

Theoretical Physic

CMB-S4 Science Book, First Edition

This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales

Dynamical dark energy in light of the latest observations

A flat Friedmann-Robertson-Walker universe dominated by a cosmological constant (Λ) and cold dark matter (CDM) has been the working model preferred by cosmologists since the discovery of cosmic acceleration1,2. However, tensions of various degrees ofsignificance are known to be present among existing datasets within the ΛCDM framework3-11. In particular, the Lyman-α forest measurement of the baryon acoustic oscillations (BAO) by the Baryon Oscillation Spectroscopic Survey3 prefers a smaller value of the matter density fraction ΩM than that preferred by cosmic microwave background (CMB). Also, the recently measured value of the Hubble constant, H0 = 73.24 ±1.74 km s-1 Mpc-1 (ref. 12), is 3.4σ higher than the 66.93 ± 0.62 km s-1Mpc-1 inferred from the Planck CMB data7. In this work, we investigate whether these tensions can be interpreted as evidence for a non-constant dynamical dark energy. Using the Kullback-Leibler divergence13 to quantify the tension between datasets, we find that the tensions are relieved by an evolving dark energy, with the dynamical dark energy model preferred at a 3.5σ significance level based on the improvement in the fit alone. While, at present, the Bayesian evidence for the dynamical dark energy is insufficient to favour it over ΛCDM, we show that, if the current best-fit dark energy happened to be the true model, it would be decisively detected by the upcoming Dark Energy Spectroscopic Instrument survey14.PostprintPeer reviewe

Photometric Properties of Jupiter Trojans Detected by the Dark Energy Survey

The Jupiter Trojans are a large group of asteroids that are coorbiting with Jupiter near its L4 and L5 Lagrange points. The study of Jupiter Trojans is crucial for testing different models of planet formation that are directly related to our understanding of solar system evolution. In this work, we select known Jupiter Trojans listed by the Minor Planet Center from the full six years data set (Y6) of the Dark Energy Survey (DES) to analyze their photometric properties. The DES data allow us to study Jupiter Trojans with a fainter magnitude limit than previous studies in a homogeneous survey with griz band measurements. We extract a final catalog of 573 unique Jupiter Trojans. Our sample include 547 asteroids belonging to L5. This is one of the largest analyzed samples for this group. By comparing with the data reported by other surveys we found that the color distribution of L5 Trojans is similar to that of L4 Trojans. We find that L5 Trojans' g - i and g - r colors become less red with fainter absolute magnitudes, a trend also seen in L4 Trojans. Both the L4 and L5 clouds consistently show such a color-size correlation over an absolute magnitude range 11 < H < 18. We also use DES colors to perform taxonomic classifications. C- and P-type asteroids outnumber D-type asteroids in the L5 Trojans DES sample, which have diameters in the 5-20 km range. This is consistent with the color-size correlation

The Dark Energy Survey Supernova Program: Corrections on Photometry Due to Wavelength-dependent Atmospheric Effects

Wavelength-dependent atmospheric effects impact photometric supernova flux measurements for ground-based observations. We present corrections on supernova flux measurements from the Dark Energy Survey Supernova Program’s 5YR sample (DES-SN5YR) for differential chromatic refraction (DCR) and wavelength-dependent seeing, and we show their impact on the cosmological parameters w and Ωm . We use g − i colors of Type Ia supernovae to quantify astrometric offsets caused by DCR and simulate point-spread functions (PSFs) using the GalSIM package to predict the shapes of the PSFs with DCR and wavelength-dependent seeing. We calculate the magnitude corrections and apply them to the magnitudes computed by the DES-SN5YR photometric pipeline. We find that for the DES-SN5YR analysis, not accounting for the astrometric offsets and changes in the PSF shape cause an average bias of +0.2 mmag and −0.3 mmag, respectively, with standard deviations of 0.7 mmag and 2.7 mmag across all DES observing bands (griz) throughout all redshifts. When the DCR and seeing effects are not accounted for, we find that w and Ωm are lower by less than 0.004 ± 0.02 and 0.001 ± 0.01, respectively, with 0.02 and 0.01 being the 1σ statistical uncertainties. Although we find that these biases do not limit the constraints of the DES-SN5YR sample, future surveys with much higher statistics, lower systematics, and especially those that observe in the u band will require these corrections as wavelength-dependent atmospheric effects are larger at shorter wavelengths. We also discuss limitations of our method and how they can be better accounted for in future surveys