8,045 research outputs found
Planck 2013 results. XXII. Constraints on inflation
We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0:9603 _ 0:0073, ruling out exact scale invariance at over 5_: Planck establishes an upper bound on the tensor-to-scalar ratio of r < 0:11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with V00 < 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n _ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns=dln k = 0:0134 _ 0:0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by __2 e_ _ 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the _2 e_ by approximately 4 as a result of slightly lowering the theoretical prediction for the ` <_ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions
A Concept Paper for a VCU Social Sciences Initiative
This project proposes the development of a Social Sciences Initiative at the undergraduate and graduate levels that will provide educational, research and service opportunities for faculty and students. These opportunities are envisioned as interdisciplinary, with a focus on community issues and priorities, and with the potential to create new links among existing educational/research units within the University. The development of a Social Sciences Initiative provides a direct link to the Mission of VCU through several of the Missionâs intents: âactivities that increase knowledge and understanding of the world and inspire and enrich teachingâ The Social Sciences Initiative will expand current activities and promote innovative teaching in an interdisciplinary manner. âdiverse educational programsâ The Social Sciences Initiative increases the diversity of educational program offerings. âdevelopment of innovative approaches to meet the changing needs of our societyâ The Social Sciences Initiative will directly address the changing societal needs through support of interdisciplinary education, research, and service. Further, this initiative is consistent with the VCU Vision in that it will âadvance a climate of scholarly inquiryâŠserve as a model of diversity in higher educationâŠaddressing urban issues in the nation and the worldâŠbuild upon its substantial foundations in theâŠapplied social sciences.â (VCU Strategic Plan for the Future of Virginia Commonwealth University, Phase II, 1998)
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Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters
This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlations of CMB data, using the hybrid approach employed previously: pixel-based at â<30 and a Gaussian approximation to the distribution of spectra at higher â . The main improvements are the use of more and better processed data and of Planck polarization data, and more detailed foreground and instrumental models, allowing further checks and enhanced immunity to systematics. Progress in foreground modelling enables a larger sky fraction. Improvements in processing and instrumental models further reduce uncertainties. For temperature, we perform an analysis of end-to-end instrumental simulations fed into the data processing pipeline; this does not reveal biases from residual instrumental systematics. The Î CDM cosmological model continues to offer a very good fit to Planck data. The slope of primordial scalar fluctuations, n s , is confirmed smaller than unity at more than 5{\sigma} from Planck alone. We further validate robustness against specific extensions to the baseline cosmology. E.g., the effective number of neutrino species remains compatible with the canonical value of 3.046. This first detailed analysis of Planck polarization concentrates on E modes. At low â we use temperature at all frequencies and a subset of polarization. The frequency range improves CMB-foreground separation. Within the baseline model this requires a reionization optical depth Ï=0.078±0.019 , significantly lower than without high-frequency data for explicit dust monitoring. At high â we detect residual errors in E, typically O(ÎŒ K 2 ); we recommend temperature alone as the high-â baseline. Nevertheless, Planck high-â polarization allows a separate determination of Î CDM parameters consistent with those from temperature alone
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Planck 2015 results. XIII. Cosmological parameters
We present results based on full-mission Planck observations of temperature and polarization anisotropies of the CMB. These data are consistent with the six-parameter inflationary LCDM cosmology. From the Planck temperature and lensing data, for this cosmology we find a Hubble constant, H0= (67.8 +/- 0.9) km/s/Mpc, a matter density parameter Omega_m = 0.308 +/- 0.012 and a scalar spectral index with n_s = 0.968 +/- 0.006. (We quote 68% errors on measured parameters and 95% limits on other parameters.) Combined with Planck temperature and lensing data, Planck LFI polarization measurements lead to a reionization optical depth of tau = 0.066 +/- 0.016. Combining Planck with other astrophysical data we find N_ eff = 3.15 +/- 0.23 for the effective number of relativistic degrees of freedom and the sum of neutrino masses is constrained to < 0.23 eV. Spatial curvature is found to be |Omega_K| < 0.005. For LCDM we find a limit on the tensor-to-scalar ratio of r <0.11 consistent with the B-mode constraints from an analysis of BICEP2, Keck Array, and Planck (BKP) data. Adding the BKP data leads to a tighter constraint of r < 0.09. We find no evidence for isocurvature perturbations or cosmic defects. The equation of state of dark energy is constrained to w = -1.006 +/- 0.045. Standard big bang nucleosynthesis predictions for the Planck LCDM cosmology are in excellent agreement with observations. We investigate annihilating dark matter and deviations from standard recombination, finding no evidence for new physics. The Planck results for base LCDM are in agreement with BAO data and with the JLA SNe sample. However the amplitude of the fluctuations is found to be higher than inferred from rich cluster counts and weak gravitational lensing. Apart from these tensions, the base LCDM cosmology provides an excellent description of the Planck CMB observations and many other astrophysical data sets
HB 69 Grocery Investment Program and Fund
In the 2018 session of the Virginia General Assembly, multiple pieces of legislation were brought to committee, proposing the creation of a fund to catalyze public-private partnerships to expand access to Virginians residing in food deserts. Through the creation of the fund, underserved communities would see the construction, rehabilitation and expansion of food retailers in their communities ameliorate food desserts
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Planck 2015 results. XIV. Dark energy and modified gravity
We study the implications of Planck data for models of dark energy (DE) and modified gravity (MG), beyond the cosmological constant scenario. We start with cases where the DE only directly affects the background evolution, considering Taylor expansions of the equation of state, principal component analysis and parameterizations related to the potential of a minimally coupled DE scalar field. When estimating the density of DE at early times, we significantly improve present constraints. We then move to general parameterizations of the DE or MG perturbations that encompass both effective field theories and the phenomenology of gravitational potentials in MG models. Lastly, we test a range of specific models, such as k-essence, f(R) theories and coupled DE. In addition to the latest Planck data, for our main analyses we use baryonic acoustic oscillations, type-Ia supernovae and local measurements of the Hubble constant. We further show the impact of measurements of the cosmological perturbations, such as redshift-space distortions and weak gravitational lensing. These additional probes are important tools for testing MG models and for breaking degeneracies that are still present in the combination of Planck and background data sets. All results that include only background parameterizations are in agreement with LCDM. When testing models that also change perturbations (even when the background is fixed to LCDM), some tensions appear in a few scenarios: the maximum one found is \sim 2 sigma for Planck TT+lowP when parameterizing observables related to the gravitational potentials with a chosen time dependence; the tension increases to at most 3 sigma when external data sets are included. It however disappears when including CMB lensing
Rebels with a Cause: VCU Student Emergency Fund
The projectâs mission is to establish a VCU Student Emergency Fund to support the well-being of students who face financial emergencies and to increase student retention and academic success. The fund will provide financial relief to students facing sudden and unexpected financial hardships that can impact their financial stability, academic success, and ability to remain enrolled at VCU. The project will support the work of student support services personnel administering the fund by providing a campus outreach plan to those who can recognize students in financial crises and refer them to the fund\u27s administrators. The project will also support the work of development personnel who will raise money for the fund by providing a donor outreach plan
Large UK retailers' initiatives to reduce consumers' emissions: a systematic assessment
In the interest of climate change mitigation, policy makers, businesses and non-governmental organisations have devised initiatives designed to reduce in-use emissions whilst, at the same time, the number of energy-consuming products in homes, and household energy consumption, is increasing. Retailers are important because they are at the interface between manufacturers of products and consumers and they supply the vast majority of consumer goods in developed countries like the UK, including energy using products. Large retailers have a consistent history of corporate responsibility reporting and have included plans and actions to influence consumer emissions within them.
This paper adapts two frameworks to use them for systematically assessing large retailersâ initiatives aimed at reducing consumersâ carbon emissions. The Framework for Strategic Sustainable Development (FSSD) is adapted and used to analyse the strategic scope and coherence of these initiatives in relation to the businessesâ sustainability strategies. The ISM âIndividual Social Materialâ framework is adapted and used to analyse how consumer behaviour change mechanisms are framed by retailers. These frameworks are used to analyse eighteen initiatives designed to reduce consumer emissions from eight of the largest UK retail businesses, identified from publicly available data.
The results of the eighteen initiatives analysed show that the vast majority were not well planned nor were they strategically coherent. Secondly, most of these specific initiatives relied solely on providing information to consumers and thus deployed a rather narrow range of consumer behaviour change mechanisms. The research concludes that leaders of retail businesses and policy makers could use the FSSD to ensure processes, and measurements are comprehensive and integrated, in order to increase the materiality and impact of their initiatives to reduce consumer emissions in use. Furthermore, retailers could benefit from exploring different models of behaviour change from the ISM framework in order to access a wider set of tools for transformative system change
An examination of the female lead roles in Show boat as a model for gender based performance practice
" The purpose of this study is to formulate a critical, gendered approach to research for informed character preparation in classic musical theatre. Jerome Kern and Oscar Hammerstein II's Show Boat provides a framework for an examination of performance practice based on stereotypes of contemporaneous gender roles. As a model for research, four areas are explored to prepare context for an original, informed interpretation of the female lead roles in Show Boat. The first area is the context of the early twentieth-century musical. American musical theatre is a fusion of European operetta, melodrama, minstrel shows, vaudeville, musical revue, musical comedy, and popular songs. Characteristic elements of each of these are found in Show Boat (1927), yet it established a marked departure from these trends. The second area is an examination of the socio-historical trends relevant to the historical era of Show Boat (1890-1927). Specific gender roles are introduced through the debate of the "Woman Question" and the stereotypes of traditional versus progressive moral values. Four societal gender stereotypes that are represented in Show Boat are the New England Victorian, the Southern Belle, the Ethnic Other, and the New Woman. The third area is a discussion of the implicit audience assumptions and stereotypes of professional women in the theatre as sexually promiscuous. These societal and theatrical gender stereotypes are then examined in relevance to the female characters of Show Boat. The fourth area is an exploration of performance practice in musical theatre. A synthesis of gender-based preparation is modeled through a method outline of character development and song analysis for "Make Believe" and "Can't Help Lovin' 'dat Man."--Abstract from author supplied metadata
I'm not buying it : a rhetorical study of mediation during Hurricane Katrina
At 6:10 AM on August 29th, 2005, with sustained winds reaching 145 miles per hour, Hurricane Katrina made landfall near Buras, Louisiana. Thousands of people were left with no access to food, or water, or shelter. The affected area was in need of immediate assistance. They needed action. Their local government, their federal government, and we as fellow citizens, as fellow human beings, watched the victims of this horrible tragedy through some form of mass media as they were forced to wait for food, water, and shelter and little was done to help them. Inherent in our national failure was a lack of understanding as to how our information was delivered to us and how it both shaped and manipulated our understanding of Hurricane Katrina. Our national mediation through mass media was neither examined nor thoroughly understood.
I examine the mediation of Hurricane Katrina through the mass media sources of television news, including both broadcast news and cable news, as well as through the Internet phenomenon of blogging. Many factors motivate our mediation within these mass media sources, including our own capitalism, our immersion in literacy and progression away from oral culture, and a continual push towards individuality and self-awareness. The purpose of this thesis then, is to examine the mediation present in Hurricane Katrina coverage in order to better understand the overarching vehicles of mediation present in the presentation of our world. Understanding where our information comes from allows us to become more active participants in the formation of our world and the ideas that govern it so that our individuality and our literacy are allowed to become compliments to our social obligations as citizens of America and our newly globalized world rather than vehicles of isolation and suffering
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