scholarly journals Beyond Schrödinger-Poisson: nonrelativistic effective field theory for scalar dark matter

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Borna Salehian ◽  
Hong-Yi Zhang ◽  
Mustafa A. Amin ◽  
David I. Kaiser ◽  
Mohammad Hossein Namjoo
Keyword(s):  
Dark Matter ◽  
Scalar Fields ◽  
Effective Field ◽  
Leading Order ◽  
Relativistic Corrections ◽  
Cosmological Context ◽  
Relativistic Regime ◽  
Klein Gordon ◽  
Relationship Of ◽  
Insight Into

Abstract Massive scalar fields provide excellent dark matter candidates, whose dynamics are often explored analytically and numerically using nonrelativistic Schrödinger-Poisson (SP) equations in a cosmological context. In this paper, starting from the nonlinear and fully relativistic Klein-Gordon-Einstein (KGE) equations in an expanding universe, we provide a systematic framework for deriving the SP equations, as well as relativistic corrections to them, by integrating out ‘fast modes’ and including nonlinear metric and matter contributions. We provide explicit equations for the leading-order relativistic corrections, which provide insight into deviations from the SP equations as the system approaches the relativistic regime. Upon including the leading-order corrections, our equations are applicable beyond the domain of validity of the SP system, and are simpler to use than the full KGE case in some contexts. As a concrete application, we calculate the mass-radius relationship of solitons in scalar dark matter and accurately capture the deviations of this relationship from the SP system towards the KGE one.

scholarly journals Dark matter annihilation into leptons through gravity portals

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Xudong Sun ◽  
Ben-Zhong Dai
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Order Term ◽  
Gravitational Interaction ◽  
Dark Matter Particle ◽  
Higgs Field ◽  
Scalar Fields ◽  
Effective Field ◽  
Leading Order ◽  
Dark Matter Annihilation

Abstract Dark matter (DM) constitutes 85% of the matter in the Universe. However, its specific particle property is still unclear. The fundamentals of DM particles subject to gravitational interaction, and that the lepton excess in cosmic rays may originate from DM particles, inspired us to investigate DM particle properties beyond the standard model. We assume that a leptophilic SU(2) doublet exists in nature as the mediator connecting DM with visible leptons. Since general relativity is not renormalizable at the quantum level, it should be regarded as an effective field theory’s leading order term. One species of the next-to-leading-order term should be operators linear to the Ricci scalar and containing scalar fields, such as the Higgs field, scalar DM, or the newly introduced SU(2) scalar doublet. These operators can cause DM annihilation through gravity portals. We analyzed constraints from the cosmic antiproton flux, DM relic abundance, cosmic positron flux, cosmic microwave background, and direct detection experiments. The result shows that there is a vast parameter space that is compatible with current experiments. DM with a mass of electroweak scale is only allowed to annihilate into leptons. We further show that the purely gravitational DM better explains the DArk Matter Particle Explorer cosmic lepton excess. Our work provides a promising mechanism for DM particles to connect with standard model particles.

Real scalar field solutions of the EKG equations including matter

2020 ◽  
pp. 2150009
Author(s):  
A. Cabo Montes de Oca ◽  
D. Suarez Fontanella
Keyword(s):  
Dark Matter ◽  
Gravitational Field ◽  
Scalar Field ◽  
Scalar Fields ◽  
Stationary Solutions ◽  
Field Interaction ◽  
Small Bodies ◽  
Real Scalar ◽  
Static Solutions ◽  
Klein Gordon

Static (not stationary) solutions of the Einstein–Klein–Gordon (EKG) equations including matter are obtained for real scalar fields. The scalar field interaction with matter is considered. The introduced coupling allows the existence of static solutions in contraposition with the case of the simpler EKG equations for real scalar fields and gravity. Surprisingly, when the considered matter is a photon-like gas, it turns out that the gravitational field intensity at large radial distances becomes nearly a constant, exerting an approximately fixed force to small bodies at any distance. The effect is clearly related with the massless character of the photon-like field. It is also argued that the gravitational field can generate a bounding attraction, that could avoid the unlimited increase in mass with the radius of the obtained here solution. This phenomenon, if verified, may furnish a possible mechanism for explaining how the increasing gravitational potential associated to dark matter, finally decays at large distances from the galaxies. A method for evaluating these photon bounding effects is just formulated in order to be further investigated.

scholarly journals Direct detection of dark matter: Precision predictions in a simplified model framework

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Christoph Borschensky ◽  
Gabriele Coniglio ◽  
Barbara Jäger ◽  
Josef Jochum ◽  
Vincent Schipperges
Keyword(s):  
Dark Matter ◽  
Effective Field Theory ◽  
Direct Detection ◽  
Effective Field ◽  
Tree Level ◽  
Leading Order ◽  
Model Framework ◽  
Simplified Models ◽  
Detection Rates ◽  
Phenomenological Studies

AbstractWe present a calculation of the next-to-leading order QCD corrections for the scattering of Dark Matter particles off nucleons in the framework of simplified models with s- and t-channel mediators. These results are matched to the Wilson coefficients and operators of an effective field theory that is generally used for the presentation of experimental results on spin-independent and spin-dependent direct detection rates. Detailed phenomenological studies illustrate the complementary reach of collider searches for Dark Matter and the direct detection experiments CRESST and XENON. In the case of cancellation effects in the tree-level contributions, one-loop corrections can have a particularly large impact on exclusion limits in the case of combined $$s + t$$ s + t -channel models.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

On Metaphysics and the Political: A Polemics of Reading Baudelaire in the 1930s

2019 ◽  
Vol 58 (2) ◽  
pp. 249-259
Author(s):  
Joseph Acquisto
Keyword(s):  
Twentieth Century ◽  
Political Crisis ◽  
The Political ◽  
Modern Poetry ◽  
Progressive Politics ◽  
The World ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

This essay examines a polemic between two Baudelaire critics of the 1930s, Jean Cassou and Benjamin Fondane, which centered on the relationship of poetry to progressive politics and metaphysics. I argue that a return to Baudelaire's poetry can yield insight into what seems like an impasse in Cassou and Fondane. Baudelaire provides the possibility of realigning metaphysics and politics so that poetry has the potential to become the space in which we can begin to think the two of them together, as opposed to seeing them in unresolvable tension. Or rather, the tension that Baudelaire animates between the two allows us a new way of thinking about the role of esthetics in moments of political crisis. We can in some ways see Baudelaire as responding, avant la lettre, to two of his early twentieth-century readers who correctly perceived his work as the space that breathes a new urgency into the questions of how modern poetry relates to the world from which it springs and in which it intervenes.

Phylogeny of actin and tubulin gene homologs in diverse eukaryotic species

2019 ◽  
Vol 79 (01S) ◽  
Author(s):  
Pawan Kumar Jayaswal ◽  
Asheesh Shanker ◽  
Nagendra Kumar Singh
Keyword(s):  
Evolutionary Relationship ◽  
Genomic Data ◽  
Gene Clusters ◽  
Species Trees ◽  
Model Species ◽  
Tubulin Gene ◽  
Tubulin Genes ◽  
Eukaryotic Species ◽  
Relationship Of ◽  
Insight Into

Actin and tubulin are cytoskeleton proteins, which are important components of the celland are conserved across species. Despite their crucial significance in cell motility and cell division the distribution and phylogeny of actin and tubulin genes across taxa is poorly understood. Here we used publicly available genomic data of 49 model species of plants, animals, fungi and Protista for further understanding the distribution of these genes among diverse eukaryotic species using rice as reference. The highest numbers of rice actin and tubulin gene homologs were present in plants followed by animals, fungi and Protista species, whereas ten actin and nine tubulin genes were conserved in all 49 species. Phylogenetic analysis of 19 actin and 18 tubulin genes clustered them into four major groups each. One each of the actin and tubulin gene clusters was conserved across eukaryotic species. Species trees based on the conserved actin and tubulin genes showed evolutionary relationship of 49 different taxa clustered into plants, animals, fungi and Protista. This study provides a phylogenetic insight into the evolution of actin and tubulin genes in diverse eukaryotic species.

scholarly journals On the three-particle analog of the Lellouch-Lüscher formula

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Fabian Müller ◽  
Akaki Rusetsky
Keyword(s):  
Field Theory ◽  
Finite Volume ◽  
Effective Field Theory ◽  
Effective Field ◽  
Infinite Volume ◽  
Leading Order ◽  
Particle Decay ◽  
Particle Decays

Abstract Using non-relativistic effective field theory, we derive a three-particle analog of the Lellouch-Lüscher formula at the leading order. This formula relates the three-particle decay amplitudes in a finite volume with their infinite-volume counterparts and, hence, can be used to study the three-particle decays on the lattice. The generalization of the approach to higher orders is briefly discussed.

scholarly journals Effective field theory analysis of dark matter-standard model interactions with spin one mediators

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Fabiola Fortuna ◽  
Pablo Roig ◽  
José Wudka
Keyword(s):  
Field Theory ◽  
Dark Matter ◽  
Standard Model ◽  
Effective Field Theory ◽  
Gamma Ray ◽  
Direct Detection ◽  
Effective Field ◽  
Indirect Detection ◽  
Theory Analysis ◽  
Invisible Decay

Abstract We analyze interactions between dark matter and standard model particles with spin one mediators in an effective field theory framework. In this paper, we are considering dark particles masses in the range from a few MeV to the mass of the Z boson. We use bounds from different experiments: Z invisible decay width, relic density, direct detection experiments, and indirect detection limits from the search of gamma-ray emissions and positron fluxes. We obtain solutions corresponding to operators with antisymmetric tensor mediators that fulfill all those requirements within our approach.

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