2,743 research outputs found
CMB Isotropy Anomalies and the Local Kinetic Sunyaev-Zel'dovich Effect
Several anomalies have been identified which may imply a breakdown of the
statistical isotropy of the cosmic microwave background (CMB). In particular,
an anomalous alignment of the quadrupole and octopole and a hemispherical power
asymmetry have increased in significance as the data have improved. There have
been several attempts to explain these observations which explore isotropy
breaking mechanisms within the early universe, but little attention has been
given to the possibility that these anomalies have their origin within the
local universe. We explore such a mechanism by considering the kinetic
Sunyaev-Zel'dovich effect due to a gaseous halo associated with the Milky Way.
Considering several physical models of an anisotropic free electron optical
depth contributed by such a halo, we find that the associated screening maps of
the primordial anisotropies have the necessary orientations to affect the
anomaly statistics very significantly, but only if the column density of free
electrons in the halo is at least an order of magnitude higher than indicated
by current observations.Comment: 10 pages, 4 figure
How to build a catalogue of linearly evolving cosmic voids
Cosmic voids provide a powerful probe of the origin and evolution of structures in the Universe because their dynamics can remain near-linear to the present day. As a result, they have the potential to connect large-scale structure at late times to early Universe physics. Existing ‘watershed’-based algorithms, however, define voids in terms of their morphological properties at low redshift. The degree to which the resulting regions exhibit linear dynamics is consequently uncertain, and there is no direct connection to their evolution from the initial density field. A recent void definition addresses these issues by considering ‘anti-haloes’. This approach consists of inverting the initial conditions of an N-body simulation to swap overdensities and underdensities. After evolving the pair of initial conditions, anti-haloes are defined by the particles within the inverted simulation that are inside haloes in the original (uninverted) simulation. In this work, we quantify the degree of non-linearity of both anti-haloes and watershed voids using the Zel’dovich approximation. We find that non-linearities are introduced by voids with radii less than 5Mpch−1, and that both anti-haloes and watershed voids can be made into highly linear sets by removing these voids
Sensory Profile, Nutritional and Shelf-Life Analysis of Cassava Par-Fried Frozen Slices Developed with Raw Cassava Roots
Cassava (Manihot esculanta Crantz) is nutritionally strategic famine reserve crop in areas of unreliable rainfall, poor soil or unfavourable climate. Presence of toxic compounds and high perishability has limited the consumption of cassava roots. An experiment was carried out to develop par-fried frozen slices of cassava in order to increase the consumption of cassava roots. Mature undamaged fresh cassava roots of cultivar ‘MU 51’ were cleaned, peeled and cut in to longitudinal cubes (0.8×0.8×10 cm). The cubes were blanched, partial fried and stored, deep freeze and stored in freezer after packing in 300 gauge LDPE pouches. The experiment revealed that extended hot water blanching for 10 minutes and initial freezing for 12 hours, increase the sensory qualities of frozen fries significantly. Moisture content, carbohydrate content, mineral content, fat content, protein content and crude fibre contents of the sample were 56.71±0.80%, 32.18±0.19%, 0.42±0.02%, 9.13±0.05%, 1.18±0.06% and 0.20±0.03% respectively. Cyanide content of the cassava frozen fries sample was 1.42±0.12 ppm. According to the microbiological and chemical testing results, cassava frozen fries were safe for consumption up to 3 months at freezer storage.Keywords: Cassava, freezing, sensory attributes, frozen fries, shelf life analysi
A Brachistochrone Approach to Reconstruct the Inflaton Potential
We propose a new way to implement an inflationary prior to a cosmological
dataset that incorporates the inflationary observables at arbitrary order. This
approach employs an exponential form for the Hubble parameter without
taking the slow-roll approximation. At lowest non-trivial order, this
has the unique property that it is the solution to the brachistochrone problem
for inflation.Comment: 13 pages, 2 figures, version matches published versio
Bourdieu, Strategy, and Identity Work: A Case from a Manufacturing Organisation in Sri Lanka
This empirical study aims to discuss how organisational actors' identity work is reflected through their strategy work, from a Bourdieusian perspective. The study is a case study which followed the qualitative research approach. The participants of the study were managers representing a cross-section of a manufacturing organisation in Sri Lanka. Twenty-six semi-structured interviews were used for the generation of the data for thematic analysis. NVivo12 data management software was used for the data management and in initial coding. It was found that managers are engaged in different identity work for self during their strategy work, in the implementation of a new organisational strategy. Further, the behaviour and practices normalised in the selected organisation through managers' strategy work reflected their identity work for other/s in way of defining other/s. The discussion was based on the theory of practice by Pierre Bourdieu (1990). Accordingly, this research shows how the identity work of position takers (newly joined and promoted organisational actors) supports shaping the practices linked with a new strategy (strategy work). Further, their identity work reflected through strategy work is also connected with their individual dispositions (habitus). The discussion further shows how individuals’ capital—mainly their cultural capital—contribute to constructing a new strategy in the selected organisational field. As implications of this study, it highlighted the contribution of the position-takers in shaping the organisation's strategy (strategy work) while engaging in identity work for self and others. Consequently, this study illustrates how organisational actors perform different social-symbolic work (identity work and strategy work) in parallel.
Keywords: Capital; Habitus, Identity work; Social-symbolic work; Strategy wor
Estimating and Forecasting Generalized Fractional Long Memory Stochastic Volatility Models
In recent years fractionally differenced processes have received a great deal of attention due to its flexibility in financial applications with long memory. This paper considers a class of models generated by Gegenbauer polynomials, incorporating the long memory in stochastic volatility (SV) components in order to develop the General Long Memory SV (GLMSV) model. We examine the statistical properties of the new model, suggest using the spectral likelihood estimation for long memory processes, and investigate the finite sample properties via Monte Carlo experiments. We apply the model to three exchange rate return series. Overall, the results of the out-of-sample forecasts show the adequacy of the new GLMSV model
Strong Lensing Probabilities in a Cosmological Model with a Running Primordial Power Spectrum
The combination of the first-year Wilkinson Microwave Anisotropy Probe (WMAP)
data with other finer scale cosmic microwave background (CMB) experiments (CBI
and ACBAR) and two structure formation measurements (2dFGRS and Lyman
forest) suggest a CDM cosmological model with a running spectral power
index of primordial density fluctuations. Motivated by this new result on the
index of primordial power spectrum, we present the first study on the predicted
lensing probabilities of image separation in a spatially flat CDM
model with a running spectral index (RSI-CDM model). It is shown that
the RSI-CDM model suppress the predicted lensing probabilities on
small splitting angles of less than about 4 compared with that of
standard power-law CDM (PL-CDM) model.Comment: 11 pages including 1 figures. Accepted for publication in Modern
Physics Letters A (MPLA), minor revision
- …