726 research outputs found
Pippi - painless parsing, post-processing and plotting of posterior and likelihood samples
Interpreting samples from likelihood or posterior probability density
functions is rarely as straightforward as it seems it should be. Producing
publication-quality graphics of these distributions is often similarly painful.
In this short note I describe pippi, a simple, publicly-available package for
parsing and post-processing such samples, as well as generating high-quality
PDF graphics of the results. Pippi is easily and extensively configurable and
customisable, both in its options for parsing and post-processing samples, and
in the visual aspects of the figures it produces. I illustrate some of these
using an existing supersymmetric global fit, performed in the context of a
gamma-ray search for dark matter. Pippi can be downloaded and followed at
http://github.com/patscott/pippi .Comment: 4 pages, 1 figure. v3: Updated for pippi 2.0. New features include
hdf5 support, out-of-core processing, inline post-processing with arbitrary
Python code in the input file, and observable-specific data cuts. Pippi can
be downloaded from http://github.com/patscott/pipp
The landscape, the swampland and the era of precision cosmology
We review the advanced version of the KKLT construction and pure d=4" role="presentation" style="display: inline; line-height: normal; font-size: 13.6px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border-width: 0px; border-style: initial; color: rgb(0, 0, 0); font-family: arial, verdana, sans-serif; position: relative;">=4d=4 de Sitter supergravity, involving a nilpotent multiplet, with regard to various conjectures that de Sitter state cannot exist in string theory. We explain why we consider these conjectures problematic and not well motivated, and why the recently proposed alternative string theory models of dark energy, ignoring vacuum stabilization, are ruled out by cosmological observations at least at the 3σ" role="presentation" style="display: inline; line-height: normal; font-size: 13.6px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border-width: 0px; border-style: initial; color: rgb(0, 0, 0); font-family: arial, verdana, sans-serif; position: relative;">33σ level, i.e. with more than 99.7%" role="presentation" style="display: inline; line-height: normal; font-size: 13.6px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border-width: 0px; border-style: initial; color: rgb(0, 0, 0); font-family: arial, verdana, sans-serif; position: relative;">99.7 .7%confidence
Planck 2018 results: IX. Constraints on primordial non-Gaussianity
Theoretical Physic
Planck 2018 results: XI. Polarized dust foregrounds
Theoretical Physic
Planck 2018 results: X. Constraints on inflation
Theoretical Physic
Planck 2018 results: II. Low frequency instrument data processing
Theoretical Physic
What can(not) be measured with ton-scale dark matter direct detection experiments
Direct searches for dark matter have prompted in recent years a great deal of
excitement within the astroparticle physics community, but the compatibility
between signal claims and null results of different experiments is far from
being a settled issue. In this context, we study here the prospects for
constraining the dark matter parameter space with the next generation of
ton-scale detectors. Using realistic experimental capabilities for a wide range
of targets (including fluorine, sodium, argon, germanium, iodine and xenon),
the role of target complementarity is analysed in detail while including the
impact of astrophysical uncertainties in a self-consistent manner. We show
explicitly that a multi-target signal in future direct detection facilities can
determine the sign of the ratio of scalar couplings , but not its
scale. This implies that the scalar-proton cross-section is left essentially
unconstrained if the assumption is relaxed. Instead, we find that
both the axial-proton cross-section and the ratio of axial couplings
can be measured with fair accuracy if multi-ton instruments using sodium and
iodine will eventually come online. Moreover, it turns out that future direct
detection data can easily discriminate between elastic and inelastic
scatterings. Finally, we argue that, with weak assumptions regarding the WIMP
couplings and the astrophysics, only the dark matter mass and the inelastic
parameter (i.e. mass splitting) may be inferred from the recoil spectra --
specifically, we anticipate an accuracy of tens of GeV (tens of keV) in the
measurement of the dark matter mass (inelastic parameter).Comment: 31 pages, 7 figures, 7 table
Euclid preparation: XXVII. A UV-NIR spectral atlas of compact planetary nebulae for wavelength calibration
ArtÃculo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMThe Euclid mission will conduct an extragalactic survey over 15 000 deg2 of the extragalactic sky. The spectroscopic channel of the Near-Infrared Spectrometer and Photometer (NISP) has a resolution of R~450 for its blue and red grisms that collectively cover the 0.93-1.89 μm range. NISP will obtain spectroscopic redshifts for 3 107 galaxies for the experiments on galaxy clustering, baryonic acoustic oscillations, and redshift space distortion. The wavelength calibration must be accurate within 5 A to avoid systematics in the redshifts and downstream cosmological parameters. The NISP pre-flight dispersion laws for the grisms were obtained on the ground using a Fabry-Perot etalon. Launch vibrations, zero gravity conditions, and thermal stabilisation may alter these dispersion laws, requiring an in-flight recalibration. To this end, we use the emission lines in the spectra of compact planetary nebulae (PNe), which were selected from a PN database. To ensure completeness of the PN sample, we developed a novel technique to identify compact and strong line emitters in Gaia spectroscopic data using the Gaia spectra shape coefficients. We obtained VLT/X-shooter spectra from 0.3 to 2.5 μm for 19 PNe in excellent seeing conditions and a wide slit, mimicking Euclid's slitless spectroscopy mode but with a ten times higher spectral resolution. Additional observations of one northern PN were obtained in the 0.80- 1.90 μm range with the GMOS and GNIRS instruments at the Gemini North Observatory. The collected spectra were combined into an atlas of heliocentric vacuum wavelengths with a joint statistical and systematic accuracy of 0.1 A in the optical and 0.3 A in the near-infrared. The wavelength atlas and the related 1D and 2D spectra are made publicly availabl
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