scholarly journals Singularities in the gravitational capture of dark matter through long-range interactions

2022 ◽  
Vol 2022 (01) ◽  
pp. 016
Author(s):  
Cristian Gaidau ◽  
Jessie Shelton
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
Capture Rate ◽  
Thermal Motion ◽  
The Sun ◽  
Long Range Interactions ◽  
Population Iii Stars ◽  
Logarithmic Sensitivity ◽  
Gravitational Capture ◽  
The Impact

Abstract We re-examine the gravitational capture of dark matter (DM) through long-range interactions. We demonstrate that neglecting the thermal motion of target particles, which is often a good approximation for short-range capture, results in parametrically inaccurate results for long-range capture. When the particle mediating the scattering process has a mass that is small in comparison to the momentum transfer in scattering events, correctly incorporating the thermal motion of target particles results in a quadratic, rather than logarithmic, sensitivity to the mediator mass, which substantially enhances the capture rate. We quantitatively assess the impact of this finite temperature effect on the captured DM population in the Sun as a function of mediator mass. We find that capture of DM through light dark photons, as in e.g. mirror DM, can be powerfully enhanced, with self-capture attaining a geometric limit over much of parameter space. For visibly-decaying dark photons, thermal corrections are not large in the Sun, but may be important in understanding long-range DM capture in more massive bodies such as Population III stars. We additionally provide the first calculation of the long-range DM self-evaporation rate.

scholarly journals Transient Unfolding and Long-Range Interactions in Viral BCL2 M11 Enable Binding to the BECN1 BH3 Domain

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1308
Author(s):  
Arvind Ramanathan ◽  
Akash Parvatikar ◽  
Srinivas C. Chennubhotla ◽  
Yang Mei ◽  
Sangita C. Sinha
Keyword(s):  
Long Range ◽  
Conformational Changes ◽  
Hydrophobic Interactions ◽  
Dynamic Simulations ◽  
Bh3 Domain ◽  
Long Range Interactions ◽  
Partial Unfolding ◽  
Binding Cleft ◽  
Inference Techniques ◽  
The Impact

Viral BCL2 proteins (vBCL2s) help to sustain chronic infection of host proteins to inhibit apoptosis and autophagy. However, details of conformational changes in vBCL2s that enable binding to BH3Ds remain unknown. Using all-atom, multiple microsecond-long molecular dynamic simulations (totaling 17 μs) of the murine γ-herpesvirus 68 vBCL2 (M11), and statistical inference techniques, we show that regions of M11 transiently unfold and refold upon binding of the BH3D. Further, we show that this partial unfolding/refolding within M11 is mediated by a network of hydrophobic interactions, which includes residues that are 10 Å away from the BH3D binding cleft. We experimentally validate the role of these hydrophobic interactions by quantifying the impact of mutating these residues on binding to the Beclin1/BECN1 BH3D, demonstrating that these mutations adversely affect both protein stability and binding. To our knowledge, this is the first study detailing the binding-associated conformational changes and presence of long-range interactions within vBCL2s.

scholarly journals Final state Sommerfeld effect on dark matter relic abundance

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiaoyi Cui ◽  
Feng Luo
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
Sommerfeld Effect ◽  
Initial State ◽  
Final State ◽  
Range Interaction ◽  
State Pair ◽  
The Masses ◽  
Relic Abundance ◽  
The Impact

Abstract If the annihilation products of dark matter (DM) are non-relativistic and if there is some long-range force between them, there can be Sommerfeld effect for the final state particles. We study this effect on DM relic abundance in the thermal freeze-out scenario. As a proof of concept, we consider the case of a DM pair annihilation into a final state pair, assuming that the mutual interactions between the two final state particles give rise to a Coulomb-like potential, and that the masses of the initial and final state particles are similar, so that both the initial and final state particles are non-relativistic. The size of the final state Sommerfeld (FSS) effect depends on the strength of the potential, as well as on the mass ratio of the final and initial state particles. We find that the impact of the FSS effect on DM relic abundance can be significant, and an electroweak sized long-range interaction is large enough to make a correction well beyond the observational accuracy. Another feature of the FSS effect is that it could be suppressed when its time scale is longer than the lifetime of the final state particles. As a corollary, we also study in the DM coannihilation scenario where the initial state Sommerfeld effect between two coannihilators could be reduced due to their instability, which may need to be taken into account for an accurate calculation of the DM relic abundance.

scholarly journals Long-range Self-interacting Dark Matter in the Sun

2015 ◽  
Vol 2015 (12) ◽  
pp. 021-021 ◽  
Author(s):  
Jing Chen ◽  
Zheng-Liang Liang ◽  
Yue-Liang Wu ◽  
Yu-Feng Zhou
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
The Sun

LONG-RANGE INTERACTIONS BETWEEN DARK-MATTER PARTICLES IN A MODEL WITH A COSMOLOGICAL, SPONTANEOUSLY-BROKEN CHIRAL SYMMETRY

2005 ◽  
Vol 20 (15) ◽  
pp. 1155-1160 ◽  
Author(s):  
SAUL BARSHAY ◽  
GEORG KREYERHOFF
Keyword(s):  
Dark Matter ◽  
Chiral Symmetry ◽  
Long Range ◽  
Gravitational Interaction ◽  
Interaction Strength ◽  
Scalar Particle ◽  
Number Density ◽  
Long Range Interactions ◽  
Pseudoscalar Particle ◽  
Coherent Effect

In a cosmological model with a chiral symmetry, there are two, dynamically-related spin-zero fields, a scalar ϕ and a pseudoscalar b. These fields have self-interactions. Spontaneous symmetry breaking results in a very massive scalar particle with mϕ≅5×1011 GeV , and a nearly massless, (Goldstone-like) pseudoscalar particle with 0<mb≲2.7×10-6 eV . One or both particles can be part of dark matter. There are coherent long-range interactions (at range ~ 1/mb≳10 cm ), from exchange of a b particle between a pair of b particles, a pair of ϕ particles, and between a ϕ and a b. We compare the strength of potentials for the different pairs to the corresponding gravitational potentials (within the same range ~ 1/mb), and show that the new force dominates between a b pair, that gravitation dominates between a ϕ pair, and that the potentials are comparable for a ϕ-b pair. The new interaction strength between a b pair is comparable to the gravitational interaction between a ϕ pair; its possibly greater coherent effect originates in the possibility that the number density of a very light b can be greater than that of a massive ϕ. We consider these results in the context of recent speculations concerning possible effects of special forces between dark-matter particles on certain galactic, and inter-galactic, properties.

The Homeland, Imprisoned and Illegal: The Impact of Marginalisation on Views of the Homeland in Kanafānī's and Khalīfa's Work

2019 ◽  
Vol 13 (1) ◽  
pp. 1-18
Author(s):  
Jedidiah Anderson
Keyword(s):  
Affect Theory ◽  
The Sun ◽  
Minor Literature ◽  
War Machine ◽  
Ghassan Kanafani ◽  
The Impact

This paper deals with the concept of Al-Waṭan, or ‘the homeland’, in Arabic in The Shell (Al-Qawqʿa) by Muṣṭafā Khalifa and Men in the Sun (Rijāl fīsh-Shams) by Ghassān Kanafānī. Analysis of how alienation from this concept has affected both Khalifa's and Kanafānī's characters is carried out through the lenses of Deleuze and Guattari's theories of rhizomatic associations and minor literature, as well as through the lens of affect theory. The paper also examines parallels between definitions of Al-Waṭan/the homeland in Ibn Manẓūr's classical dictionary Lisān al-ʿArab and Deleuze and Guattari's concepts of the war machine and the apparatus of capture.

Sign in / Sign up

Export Citation Format

Share Document