1,008 research outputs found
Can Dark Matter be an artifact of extended theories of gravity?
In this article, we propose different background models of extended theories
of gravity, which are minimally coupled to the SM fields, to explain the
possibility of genesis of dark matter without affecting the SM particle sector.
We modify the gravity sector by allowing quantum corrections motivated from (1)
local gravity and (2) non-minimally coupled gravity with SM sector and
dilaton field. Next we apply conformal transformation on the metric to
transform the action back to the Einstein frame. We also show that an effective
theory constructed from these extended theories of gravity and SM sector looks
exactly the same. Using the relic constraint observed by Planck 2015, we
constrain the scale of the effective field theory () as well as
the dark matter mass (). We consider two cases- (1) light dark matter (LDM)
and (2) heavy dark matter (HDM), and deduce upper bounds on thermally averaged
cross section of dark matter annihilating to SM particles. Further we show that
our model naturally incorporates self interactions of dark matter. Using these
self interactions, we derive the constraints on the parameters of the (1) local
gravity and (2) non-minimally coupled gravity from dark matter self
interaction. Finally, we propose some different UV complete models from a
particle physics point of view, which can give rise to the same effective
theory that we have deduced from extended theories of gravity.Comment: 45 pages, 8 figures, Accepted for publication in European Physical
Journal
Misleading Estimation of Backwardness through NITI Aayog SDG index: A study to find loopholes and construction of alternative index with the help of Artificial Intelligence
UNDP Rio +20 summit in 2012 evolved a set of indicators to realise the targets of SDGs within a deadline. Measurement of the performances under these goals has followed the methodology as developed by UNDP which is nothing but the simple average of performances of the indicators under different domains. This work concludes that this methodology to measure the goal-wise as well as the composite performances is suffering from major shortcomings and proposes an alternative using the ideas of artificial intelligence. Here it is accepted that the indicators under different goals are inter-related and hence constructing index through simple average is misleading. Moreover the methodologies under the existing indices have failed to assign weights to different indicators.
This work is based on secondary data and the goal-wise indices have been determined through normalised sigmoid functions. These goal-wise indices are plotted on a radar and the area of the radar is treated as measure under composite SDG performance. The whole work is presented through an artificial neural network.
Observed that the goal-wise index as developed and tested here has shown that the UNDP as well as NITI Aayog index has delivered exaggerated values of goal-wise as well as composite performances
Materialized View Replacement using Markovs Analysis
Materialized view is used in large data centric applications to expedite
query processing. The efficiency of materialized view depends on degree of
result found against the queries over the existing materialized views.
Materialized views are constructed following different methodologies. Thus the
efficacy of the materialized views depends on the methodology based on which
these are formed. Construction of materialized views are often time consuming
and moreover after a certain time the performance of the materialized views
degrade when the nature of queries change. In this situation either new
materialized views could be constructed from scratch or the existing views
could be upgraded. Fresh construction of materialized views has higher time
complexity hence the modification of the existing views is a better
solution.Modification process of materialized view is classified under
materialized view maintenance scheme. Materialized view maintenance is a
continuous process and the system could be tuned to ensure a constant rate of
performance. If a materialized view construction process is not supported by
materialized view maintenance scheme that system would suffer from performance
degradation. In this paper a new materialized view maintenance scheme is
proposed using markovs analysis to ensure consistent performance. Markovs
analysis is chosen here to predict steady state probability over initial
probability
A pregnancy with GDM, hypothyroidism, polyhydrramnios with history of treatment for subfertility
Gestational diabetes (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy. Although it is a well-known cause of pregnancy complications, its epidemiology has not been studied systematically. There are several identifiable predisposing factors for GDM, and in the absence of risk factors, the incidence of GDM is low. Low thyroid hormone levels in early pregnancy are a risk factor for GDM incidence. Although gestational hyperthyroidism is uncommon (0.2%), hypothyroidism (autoimmune disease or suboptimal iodine intake) occurs in 2.5% of women and is predictive of reduced neonatal and child neuropsychological development and maternal obstetric complications. It is well documented that thyroid disorders are associated with maternal and fetal complications during gestation and sequelea after delivery. The case-finding strategy does not solve the serious problem of leaving undiagnosed and untreated patients without risk factors. In the absence of strong evidence that support universal thyroid screening in pregnancy, current guidelines suggest a case-finding approach targeting thyroid function testing in high-risk groups. A couple have history of sub-fertility. Patient conceived following treatment. During pregnancy, GDM developed and later half of pregnancy was complicated by polyhydramnios. Baby was delivered by LSCS due to PPROM
Shared Versus Separate Networks - The Impact of Reprovisioning
As networks improve and new services emerge, questions arise that affect service deployments and network choices. The Internet is arguably a successful example of a network shared by many services. However, combining heterogeneous services on the same network need not always be the right answer, and technologies such as virtualization make deploying new services on separate networks increasingly more viable. So, which is the right option? The question is not unique to networks, and there is a large body of work in the manufacturing systems literature that explores the trade-off between flexible and dedicated plants. This paper highlights an important feature missing from these earlier works, namely, the ability to ``reprovision\u27\u27 resources in response to changes in demand. It demonstrates that this feature alone can affect the choice of network solutions, and argues for models that incorporate it
Functionality-rich Versus Minimalist Platforms: A Two-sided Market Analysis
Should a new ``platform\u27\u27 target a functionality-rich but complex andexpensive design or instead opt for a bare-bone but cheaper one? This is afundamental question with profound implications for the eventual success ofany platform. A general answer is, however, elusive as it involves a complextrade-off between benefits and costs. The intent of this paper is tointroduce an approach based on standard tools from the fields of marketing andeconomics, which can offer some insight into this difficult question. Wedemonstrate its applicability by developing and solving a generic model thatincorporates key interactions between platform stakeholders. The solutionconfirms that the ``optimal\u27\u27 number of features a platform should offerstrongly depends on variations in cost factors. More interestingly, it revealsa high sensitivity to small relative changes in those costs. The paper\u27scontribution and motivation are in establishing the potential of such across-disciplinary approach for providing qualitative and quantitativeinsights into the complex question of platform design
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