scholarly journals Searches for Exotic Interactions Using Neutrons

Symmetry ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
William Michael Snow ◽  
Chris Haddock ◽  
Ben Heacock
Keyword(s):  
Dark Matter ◽  
Recent Work ◽  
Epithermal Neutron ◽  
Heavy Nuclei ◽  
Cold Neutrons ◽  
Slow Neutrons

Slow neutrons possess several advantageous properties which make them useful probes for a variety of exotic interactions, including some that can form at least some components of the dark matter of interest for this issue of Symmetry. We discuss the relevant neutron properties, describe some of the recent work that has been done along these lines using neutron experiments mainly with cold and ultra-cold neutrons, and outline some interesting and exciting opportunities which can be pursued using resonant epithermal neutron interactions in heavy nuclei.

On the Cross Section of Heavy Nuclei for Slow Neutrons

1935 ◽  
Vol 48 (4) ◽  
pp. 367-372 ◽  
Author(s):  
J. H. van Vleck
Keyword(s):  
Cross Section ◽  
Heavy Nuclei ◽  
The Cross ◽  
Slow Neutrons

scholarly journals Modelling Galaxy Populations in the Era of Big Data

2014 ◽  
Vol 10 (S306) ◽  
pp. 304-306
Author(s):  
S. G. Murray ◽  
C. Power ◽  
A. S. G. Robotham
Keyword(s):  
Dark Matter ◽  
Big Data ◽  
Open Source ◽  
Recent Work ◽  
Mass Function ◽  
Dark Matter Halo ◽  
Square Kilometre Array ◽  
Galaxy Surveys ◽  
Software Frameworks ◽  
Galaxy Populations

AbstractThe coming decade will witness a deluge of data from next generation galaxy surveys such as the Square Kilometre Array and Euclid. How can we optimally and robustly analyse these data to maximise scientific returns from these surveys? Here we discuss recent work in developing both the conceptual and software frameworks for carrying out such analyses and their application to the dark matter halo mass function. We summarise what we have learned about the HMF from the last 10 years of precision CMB data using the open-source HMFcalc framework, before discussing how this framework is being extended to the full Halo Model.

On the Splitting of Heavy Nuclei by Slow Neutrons

1939 ◽  
Vol 55 (10) ◽  
pp. 987-987 ◽  
Author(s):  
J. Frenkel
Keyword(s):  
Heavy Nuclei ◽  
Slow Neutrons

scholarly journals Building Galactic Disks in Triaxial Dark Matter Halos

2006 ◽  
Vol 2 (S235) ◽  
pp. 24-28
Author(s):  
Isaac Shlosman
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Star Formation ◽  
Numerical Simulations ◽  
Recent Work ◽  
Stellar Evolution ◽  
Dark Matter Halos ◽  
Local Universe ◽  
Broad Agreement ◽  
Formation And Evolution

AbstractWe review our recent work on the formation and evolution of disks within triaxial dark matter (DM) halos by means of numerical simulations, including star formation and feedback from stellar evolution. The growing disks are strongly influenced by shapes of DM halos and modify them in turn. Disk parameters are in a broad agreement with those in the local universe. Gas-rich stellar bars grow in tandem with the disk and facilitate the angular momentum redistribution in the system and radial gas inflow. Nested bars appear to form as a by-product. Interactions between various non-axisymmetric components—bars, disks and halos lead to decay of bars or washing out of ellipticity in the inner halo.

scholarly journals Central Black Holes and Dark Halos in Elliptical Galaxies

1995 ◽  
Vol 164 ◽  
pp. 215-225
Author(s):  
P.T. De Zeeuw
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Recent Work ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Massive Black Holes ◽  
Area Of Interest

Studies of the mass–to–light ratio M/L as a function of radius in a galaxy usually focus on: a) the existence of dark matter in and around galaxies, and b) the presence of massive black holes in their nuclei. Here we concentrate on elliptical galaxies, and summarize some recent work in both areas. We refer to more extensive reviews for earlier developments (Schwarzschild, 1954; Trimble, 1987; Ashman, 1992; Kormendy, 1993). A third area of interest is the behavior of the stellar populations as a function of radius, and its effect on M/L (e.g., Peletier, 1989). We will not discuss this here.

scholarly journals The Outer Halos of Early-Type Galaxies

2014 ◽  
Vol 10 (S311) ◽  
pp. 31-35
Author(s):  
Ortwin Gerhard ◽  
Magda Arnaboldi ◽  
Alessia Longobardi
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Recent Work ◽  
Galaxy Evolution ◽  
Planetary Nebulae ◽  
Early Type ◽  
Mass Distributions ◽  
Central Galaxy ◽  
Stellar Halo ◽  
Intracluster Light

AbstractThe outer halos of massive early-type galaxies (ETGs) are dark matter dominated and may have formed by accretion of smaller systems during galaxy evolution. Here a brief report is given of some recent work on the kinematics, angular momentum, and mass distributions of simulated ETG halos, and of corresponding properties of observed halos measured with planetary nebulae (PNe) as tracers. In the outermost regions of the Virgo-central galaxy M87, the PN data show that the stellar halo and the co-spatial intracluster light are distinct kinematic components.

scholarly journals ‘Observing’ unrelaxed clusters in dark matter simulations

2019 ◽  
Vol 490 (1) ◽  
pp. 773-783
Author(s):  
Ian D Roberts ◽  
Laura C Parker
Keyword(s):  
Dark Matter ◽  
Recent Work ◽  
Three Dimensional ◽  
Line Of Sight ◽  
One Dimensional ◽  
The Galaxy ◽  
Velocity Information ◽  
Galaxy Populations ◽  
Non Gaussian ◽  
The Impact

ABSTRACT We present a detailed study of relaxed and unrelaxed galaxy clusters in a large dark matter only simulation. Recent work has demonstrated clear differences between the galaxy populations in clusters that have Gaussian velocity distributions (relaxed) compared to those that do not (unrelaxed). To directly compare with observations, we identify unrelaxed clusters in the simulations using one-dimensional velocity distributions. We show that non-Gaussian clusters have had recent major mergers and enhanced rates of galaxy infall relative to systems with Gaussian velocity profiles. Furthermore, we find that the fraction of non-Gaussian clusters increases strongly with cluster mass and modestly with redshift. For comparison, we also make use of three-dimensional information available in the simulations to explore the impact of projection on observational measurements. Differences between Gaussian and non-Gaussian clusters are much stronger when three-dimensional information is considered, which demonstrates that the strength of oberserved trends with cluster dynamics are diluted because observed velocity information is limited to one line-of-sight.

scholarly journals Technical comment on the paper of Dessert et al. "The dark matter interpretation of the 3.5 keV line is inconsistent with blank-sky observations"

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Alexey Boyarsky ◽  
Denys Malyshev ◽  
Oleg Ruchayskiy ◽  
Denys Savchenko
Keyword(s):  
Dark Matter ◽  
Recent Work ◽  
Background Modeling ◽  
Line Flux ◽  
Order Of Magnitude

An unidentified line at energy around 3.5 keV was detected in the spectra of dark matter-dominated objects. Recent work [1] used 30~Msec of XMM-Newton blank-sky observations to constrain the admissible line flux, challenging its dark matter decay origin. We demonstrate that these bounds are overestimated by more than an order of magnitude due to improper background modeling. Therefore, the dark matter interpretation of the 3.5~keV signal remains viable.

What sentimentalists should say about emotion

2019 ◽  
Vol 42 ◽  
Author(s):  
Charlie Kurth
Keyword(s):  
Moral Judgment ◽  
Recent Work ◽  
Relevant Information ◽  
Moral Cognition ◽  
Multilevel Structure

Abstract Recent work by emotion researchers indicates that emotions have a multilevel structure. Sophisticated sentimentalists should take note of this work – for it better enables them to defend a substantive role for emotion in moral cognition. Contra May's rationalist criticisms, emotions are not only able to carry morally relevant information, but can also substantially influence moral judgment and reasoning.

The Sun as a Magnetic Star

1976 ◽  
Vol 32 ◽  
pp. 457-463
Author(s):  
John M. Wilcox ◽  
Leif Svalgaard
Keyword(s):  
Recent Work ◽  
Rotation Axis ◽  
Polar Field ◽  
Magnetic Star ◽  
Rotational Axis ◽  
Field Variation ◽  
The Sun ◽  
Arbitrary Angle ◽  
Solar Magnetism ◽  
Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

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