Supernova cosmology: legacy and future

The discovery of dark energy by the first generation of high-redshift supernova surveys has generated enormous interest beyond cosmology and has dramatic implications for fundamental physics. Distance measurements using supernova explosions are the most direct probes of the expansion history of the Universe, making them extremely useful tools to study the cosmic fabric and the properties of gravity at the largest scales. The past decade has seen the confirmation of the original results. Type Ia supernovae are among the leading techniques to obtain high-precision measurements of the dark energy equation of state parameter, and in the near future, its time dependence. The success of these efforts depends on our ability to understand a large number of effects, mostly of astrophysical nature, influencing the observed flux at Earth. The frontier now lies in understanding if the observed phenomenon is due to vacuum energy, albeit its unnatural density, or some exotic new physics. Future surveys will address the systematic effects with improved calibration procedures and provide thousands of supernovae for detailed studies.Comment: Invited review, Annual Review of Nuclear and Particle Science (submitted version

Symbiots: Conceptual interventions into energy systems

Symbiots set out to examine values such as ease-of-use, comfort, and rationality assumed within conventions of ‘good design’, in order to expose issues related to energy consumption and current human- (versus eco-) centered design paradigms. Exploring re-interpretations of graphical patterns, architectural configurations and electrical infrastructure typical in Swedish cities, Symbiots takes the form of a photo series in the genre of contemporary hyper-real art photography. Painting a vivid picture of alternatives to current local priorities around energy consumption, the three design concepts depicted are strangely familiar, alternatively humorous and sinister

Coastal fish indicators response to natural and anthropogenic drivers–variability at temporal and different spatial scales

AbstractEcological indicators are increasingly used in marine and freshwater management but only few are developed towards full operationalization with known patterns of variability and documented responses to natural and anthropogenic environmental drivers. Here, we evaluate potential sources of indicator variability at two different spatial scales in three coastal fish-based indicators of environmental status in the Baltic Sea; abundance of cyprinids, abundance of perch and the proportion of larger perch. The study was performed on a data set covering 41 monitoring areas subject to different levels of anthropogenic impact, at a latitudinal range of 56–66°N and a salinity range of 2–8. Interannual variation was clearly minor relative to spatial variation. Small-scale spatial variation was related to water depth, wave exposure and water temperature. The remaining variation was assessed in relation to differences in natural and anthropogenic drivers between monitoring areas. Cyprinids showed a clear inverse relationship to water transparency, which was used as a proxy for eutrophication, indicating increased abundances in nutrient enriched areas. None of the indicators showed an expected negative relationship to the level of coastal commercial fisheries catches. Rather, a positive relationship for Perch suggested that the coastal fisheries were concentrated to areas with strong perch populations in the studied areas. The effect of salinity and climate (temperature during the growth season) among monitoring areas were small. The results emphasize the importance of assigning area-specific boundary levels to define good environmental status in the coastal fish indicators, in order to account for natural sources of variability. Further, although long-term monitoring in reference areas is crucial for obtaining a historical baseline, our results suggest that the status assessment of coastal fish would generally gain precision by increasingly including spatially based assessments. We propose that similar analytical approaches could be applied to other ecosystem components, especially in naturally heterogenic environments, in order to separate indicator variability attributed to potential anthropogenic impact

Statistical tests of sterile neutrinos using cosmology and short-baseline data

In this paper we revisit the question of the information which cosmology provides on the scenarios with sterile neutrinos invoked to describe the SBL anomalies using Bayesian statistical tests. We perform an analysis of the cosmological data in $\Lambda$CDM$+r+\nu_s$ cosmologies for different cosmological data combinations, and obtain the marginalized cosmological likelihood in terms of the two relevant parameters, the sterile neutrino mass $m_s$ and its contribution to the energy density of the early Universe $N_{\rm eff}$. We then present an analysis to quantify at which level a model with one sterile neutrino is (dis)favoured with respect to a model with only three active neutrinos, using results from both short-baseline experiments and cosmology. We study the dependence of the results on the cosmological data considered, in particular on the inclusion of the recent BICEP2 results and the SZ cluster data from the Planck mission. We find that only when the cluster data is included the model with one extra sterile neutrino can become more favoured that the model with only the three active ones provided the sterile neutrino contribution to radiation density is suppressed with respect to the fully thermalized scenario. We have also quantified the level of (in)compatibility between the sterile neutrino masses implied by the cosmological and SBL results.Comment: 23 pages, 4 figure

The Hapless State of Amyotrophic Lateral Sclerosis in India: A comprehensive look at life and medical services for ALS patients in rural Himachal Pradesh

Amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease is a neurodegenerative disorder that leads to paralysis. The disease requires a high amount of medical intervention and interdisciplinary focus to achieve quality of life for patients. This study looks at ALS patient’s lifestyles, their access to these medical devices, Indian therapeutic approaches and policy that impacts patients in Shimla, Himachal Pradesh. As caretakers have a critical part in the care for this disease, their lives were also considered in the case studies. It was found that ALS patients are not experiencing access to medical devices necessary for life because of physical accessibility barriers, financial barriers and a lack of knowledge about the disease. Knowledge of government healthcare financial policy and awareness of services offered by Asha Ek Hope to improve the access to these devices for ALS patients was not found in the study. Access to one of two pharmaceuticals was found to be achieved across the study group, however, the treatment methods for edaravone were inaccessible because of physical barriers and finances. With no known cure for the disease, the focus switches towards the Indian perspective on life and offering a death with dignity and comfort. It was found that ALS patients and their caregroups do not support passive euthanasia as determined by a 2018 Supreme Court decision while palliative care was found to be inexistent despite a dire need for this supportive care for families and patients living with ALS. The findings of this study shed light on the dire need for support of these patients in accessing devices and political advocacy. This study also brings public health awareness to the rare disease community in India—breaking down the public health and rare disease oxymoron

Suppressing Unwanted Autobiographical Memories Reduces Their Automatic Influences: Evidence from Electrophysiology and an Implicit Autobiographical Memory Test

The present study investigated the extent to which people can suppress unwanted autobiographical memories in a mock crime memory detection context. Participants encoded sensorimotor-rich memories by enacting a lab crime (stealing a ring) and received direct suppression instructions so as to evade guilt detection in a brainwave-based concealed information test. Aftereffects of suppression on automatic memory processes were measured in an autobiographical implicit association test (aIAT). Results showed that suppression attenuated brainwave activity (P300) that is associated with crime-relevant memory retrieval, rendering innocent and guilty/suppression participants indistinguishable. However, guilty/suppression and innocent participants could nevertheless be discriminated via the late posterior negative slow wave, which may reflect the need to monitor response conflict arising between voluntary suppression and automatic recognition processes. Lastly, extending recent findings that suppression can impair implicit memory processes; we provide novel evidence that suppression reduces automatic cognitive biases that are otherwise associated with actual autobiographical memories

Dark matter annihilation at the galactic center

If cold dark matter is present at the galactic center, as in current models of the dark halo, it is accreted by the central black hole into a dense spike. Particle dark matter then annihilates strongly inside the spike, making it a compact source of photons, electrons, positrons, protons, antiprotons, and neutrinos. The spike luminosity depends on the density profile of the inner halo: halos with finite cores have unnoticeable spikes, while halos with inner cusps may have spikes so bright that the absence of a detected neutrino signal from the galactic center already places interesting upper limits on the density slope of the inner halo. Future neutrino telescopes observing the galactic center could probe the inner structure of the dark halo, or indirectly find the nature of dark matter.Comment: 4 pages, 5 figure

Eisenstein congruences for split reductive groups

We present a general conjecture on congruences between Hecke eigenvalues of parabolically induced and cuspidal automorphic representations of split reductive groups, modulo divisors of critical values of certain L-functions. We examine the consequences in several special cases and use the Bloch–Kato conjecture to further motivate a belief in the congruences

New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation

We compute the electromagnetic radiative corrections to all leading annihilation processes which may occur in the Galactic dark matter halo, for dark matter in the framework of supersymmetric extensions of the Standard Model (MSSM and mSUGRA), and present the results of scans over the parameter space that is consistent with present observational bounds on the dark matter density of the Universe. Although these processes have previously been considered in some special cases by various authors, our new general analysis shows novel interesting results with large corrections that may be of importance, e.g., for searches at the soon to be launched GLAST gamma-ray space telescope. In particular, it is pointed out that regions of parameter space where there is a near degeneracy between the dark matter neutralino and the tau sleptons, radiative corrections may boost the gamma-ray yield by up to three or four orders of magnitude, even for neutralino masses considerably below the TeV scale, and will enhance the very characteristic signature of dark matter annihilations, namely a sharp step at the mass of the dark matter particle. Since this is a particularly interesting region for more constrained mSUGRA models of supersymmetry, we use an extensive scan over this parameter space to verify the significance of our findings. We also re-visit the direct annihilation of neutralinos into photons and point out that, for a considerable part of the parameter space, internal bremsstrahlung is more important for indirect dark matter searches than line signals.Comment: Replaced Fig. 2c which by mistake displayed the same spectrum as Fig. 2d; the radiative corrections reported here are now implemented in DarkSUSY which is available at http://www.physto.se/~edsjo/darksusy