Cosmos, Chaos and Order: Mapping as Knowing

Leonardo ◽  
2021 ◽  
Vol 54 (1) ◽  
pp. 107-114
Author(s):  
Priyamvada Natarajan
Keyword(s):  
Dark Matter ◽  
Observational Data ◽  
Indirect Evidence ◽  
Current Understanding ◽  
Empirical Science ◽  
Controlled Experiments ◽  
Matter Component ◽  
Observational Science

Observation and experiment are seen as the cornerstones of empirical science. Astronomy, an inherently observational science, affords a case study of a discipline in which controlled experiments cannot be performed. The author argues that in such disciplines maps and mapping serve to interpolate intellectually between observation and experiment. This is particularly noticeable in the early conceptions of cosmos and changes in worldview wherein major cognitive shifts are encoded in maps. With historical advances in map-making techniques, the epistemic purposes served by maps have also evolved significantly. Maps in astronomy today are deployed as powerful visual devices that record and transmute observational data to support theoretical ideas underpinning our current understanding of the cosmos. One example is dark matter maps, which offer compelling indirect evidence for the existence of the elusive dominant matter component that shapes our universe: dark matter.

scholarly journals MODIFIED AVERAGING PROCESSES IN COSMOLOGY AND THE STRUCTURED FRW MODEL

2009 ◽  
Vol 18 (07) ◽  
pp. 1177-1192 ◽  
Author(s):  
SHAHRAM KHOSRAVI ◽  
REZA MANSOURI ◽  
EHSAN KOURKCHI
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Volume Averaging ◽  
Matter Density ◽  
Singular Behavior ◽  
Gauge Dependence ◽  
Frw Model ◽  
Matter Component ◽  
Ltb Metric

We study the volume averaging of inhomogeneous metrics within GR and discuss its shortcomings, such as gauge dependence, singular behavior as a result of caustics, and causality violations. To remedy these shortcomings, we suggest some modifications to this method. As a case study we focus on the inhomogeneous structured FRW model based on a flat LTB metric. The effect of averaging is then studied in terms of an effective backreaction fluid. It is shown that, contrary to the claims in the literature, the backreaction fluid behaves like a dark matter component, instead of dark energy, having a density of the order of 10-5 times the matter density, and, most importantly, it is gauge-dependent.

scholarly journals Cosmological searches for a noncold dark matter component

2017 ◽  
Vol 96 (4) ◽  
Author(s):  
Stefano Gariazzo ◽  
Miguel Escudero ◽  
Roberta Diamanti ◽  
Olga Mena
Keyword(s):  
Dark Matter ◽  
Matter Component

scholarly journals Praktik Pernikahan dalam Masyarakat Lokal: Agensi versus Agama

2020 ◽  
Vol 4 (1) ◽  
pp. 35-52
Author(s):  
Budiman Pohan ◽  
Muhamad Fadhil Nurdin
Keyword(s):  
Observational Data ◽  
Study Design ◽  
Research Method ◽  
Power Relations ◽  
Local Elites ◽  
Case Study Design ◽  
Local Elite ◽  
Qualitative Descriptive ◽  
Dialectical Process

This study aims to describe the dialectical process between local agents and religious structures in the practice of marriage in Padang Sidempuan. The research method is qualitative descriptive with a case study design that focuses on narrating the objective conditions of agent and structure duality. Informants were chosen purposively, supported by observational data, interviews, and documentation. Data analyzed through the process of collection, reduction, exposition, verification, and conclusion. The results showed that: 1) Conceptually, the practice of marriage experienced practical distortions that were configured through consensus of sharia and local elites; 2) the practice of marriage is a phenomenon of the duality of agents and structuring each other; 3) agent habitus is dominated by Mandailing culture through power relations and surplus capital of the local elite compared to the sharia procedure of religious structure. However, the competence of agents is able to compress marital rules into semi-complex; 4) the importance of promoting religious habituation strategies through internalization and dissemination of alternative sharia marriage practices.

scholarly journals Developing an Analytical Solution that Mimics Simulation Modeling for Construction Planning: Earthwork Case

2019 ◽  
pp. 552-562
Author(s):  
Waleed Shakeel ◽  
Ming Lu
Keyword(s):  
Analytical Solution ◽  
Dynamic System ◽  
Simulation Modeling ◽  
High Accuracy ◽  
Analytical Tool ◽  
Controlled Experiments ◽  
Cost Estimating ◽  
Construction Planning ◽  
Using Data

Deriving a reliable earthwork job cost estimate entails analysis of the interaction of numerous variables defined in a highly complex and dynamic system. Using simulation to plan earthwork haul jobs delivers high accuracy in cost estimating. However, given practical limitations of time and expertise, simulation remains prohibitively expensive and rarely applied in the construction field. The development of a pragmatic tool for field applications that would mimic simulation-derived results while consuming less time was thus warranted. In this research, a spreadsheet based analytical tool was developed using data from industry benchmark databases (such as CAT Handbook and RSMeans). Based on a case study, the proposed methodology outperformed commonly used estimating methods and compared closely to the results obtained from simulation in controlled experiments.

scholarly journals Two natural scenarios for dark matter particles coexisting with supersymmetry

2019 ◽  
Vol 34 (02) ◽  
pp. 1930001 ◽  
Author(s):  
Maxwell Throm ◽  
Reagan Thornberry ◽  
John Killough ◽  
Brian Sun ◽  
Gentill Abdulla ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cross Sections ◽  
Higgs Sector ◽  
Weakly Interacting Massive Particles ◽  
Indirect Detection ◽  
Experimental Facilities ◽  
Direct And Indirect Detection ◽  
Extended Higgs Sector ◽  
Matter Component ◽  
Multicomponent Model

We describe two natural scenarios in which both dark matter, weakly interacting massive particles (WIMPs) and a variety of supersymmetric partners should be discovered in the foreseeable future. In the first scenario, the WIMPs are neutralinos, but they are only one component of the dark matter, which is dominantly composed of other relic particles such as axions. (This is the multicomponent model of Baer, Barger, Sengupta and Tata.) In the second scenario, the WIMPs result from an extended Higgs sector and may be the only dark matter component. In either scenario, both the dark matter WIMP and a plethora of other neutral and charged particles await discovery at many experimental facilities. The new particles in the second scenario have far weaker cross-sections for direct and indirect detection via their gauge interactions, which are either momentum-dependent or second-order. However, as we point out here, they should have much stronger interactions via the Higgs. We estimate that their interactions with fermions will then be comparable to (although not equal to) those of neutralinos with a corresponding Higgs interaction. It follows that these newly proposed dark matter particles should be within the reach of emerging and proposed facilities for direct, indirect and collider-based detection.

scholarly journals Electroweak corrections in a pseudo Nambu-Goldstone Dark Matter model revisited

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Seraina Glaus ◽  
Margarete Mühlleitner ◽  
Jonas Müller ◽  
Shruti Patel ◽  
Tizian Römer ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Parameter Space ◽  
Goldstone Boson ◽  
Indirect Evidence ◽  
Tree Level ◽  
Dark Matter Candidate ◽  
Nucleon Scattering ◽  
The Cross ◽  
Electroweak Corrections

Abstract Having so far only indirect evidence for the existence of Dark Matter a plethora of experiments aims at direct detection of Dark Matter through the scattering of Dark Matter particles off atomic nuclei. For the correct interpretation and identification of the underlying nature of the Dark Matter constituents higher-order corrections to the cross section of Dark Matter-nucleon scattering are important, in particular in models where the tree-level cross section is negligibly small. In this work we revisit the electroweak corrections to the dark matter-nucleon scattering cross section in a model with a pseudo Nambu-Goldstone boson as the Dark Matter candidate. Two calculations that already exist in the literature, apply different approaches resulting in different final results for the cross section in some regions of the parameter space leading us to redo the calculation and analyse the two approaches to clarify the situation. We furthermore update the experimental constraints and examine the regions of the parameter space where the cross section is above the neutrino floor but which can only be probed in the far future.

scholarly journals The Search for Dark Matter in Draco and Ursa Minor: A Three Year Progress Report

1987 ◽  
Vol 117 ◽  
pp. 153-160 ◽  
Author(s):  
M. Aaronson ◽  
E. Olszewski
Keyword(s):  
Dark Matter ◽  
Velocity Dispersion ◽  
Progress Report ◽  
Radial Velocities ◽  
Circumstantial Evidence ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Stellar Velocity ◽  
Atmospheric Motions ◽  
Matter Component

We report the cumulative results of an on-going effort to measure the stellar velocity dispersion in two nearby dwarf spheroidal galaxies. Radial velocities having an accuracy ≲ 2 km s−1 have now been secured for ten stars in Ursa Minor and eleven stars in Draco (including 16 K giants and 5 C types). Most objects have been observed at two or more epochs. Stars having non-variable velocities yield in both dwarfs a large (∼ 10 km s−1) dispersion. These results cannot be explained by atmospheric motions, and circumstantial evidence suggests that the effects of undetected binaries are also not likely to be important. Instead, it seems that both spheroidals contain a substantial dark matter component, which therefore must be “cold” in form.

scholarly journals Muon g−2 and dark matter suggest nonuniversal gaugino masses: SU(5)×A4 case study at the LHC

2018 ◽  
Vol 97 (11) ◽  
Author(s):  
Alexander S. Belyaev ◽  
Steve F. King ◽  
Patrick B. Schaefers
Keyword(s):  
Dark Matter ◽  
Gaugino Masses

scholarly journals Evidence for Light-weight Local Group Dwarf Spheroidal Galaxies

2004 ◽  
Vol 220 ◽  
pp. 365-366
Author(s):  
J. R. Kuhn ◽  
D. Kocevski
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Local Group ◽  
Light Weight ◽  
Natural Explanation ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Matter Component ◽  
Morphological State ◽  
Spheroidal Galaxies

A simple and natural explanation for the dynamics and morphology of the Local Group Dwarf Spheroidal galaxies, Draco (Dra) and Ursa Minor (UMi), is that they are weakly unbound stellar systems with no significant dark matter component. A gentle, but persistent, Milky Way (MW) tide has left them in their current kinematic and morphological state (the “parametric tidal excitation”). A new test of a dark matter dominated dS potential follows from a careful observation of the “clumpiness” of the dS stellar surface density.

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