Cold Dark Matter as Compact Composite Objects

Abstract

Dark Matter (DM) being the vital ingredient in the cosmos, still remains a mystery. Standard assumption is that the collisionless cold dark matter (CCDM) particles are represented by some weakly interacting fundamental fields which can not be associated with any standard quarks or leptons. However, recent analyses of structure on galactic and sub-galactic scales have suggested discrepancies and stimulated numerous alternative proposals including, e.g. Self-Interacting dark matter, Self-Annihilating dark matter, Decaying dark matter, to name just a few. We propose the alternative to the standard assumption about the nature of DM particles (which are typically assumed to be weakly interacting fundamental point -like particles, yet to be discovered). Our proposal is based on the idea that DM particles are strongly interacting composite macroscopically large objects which made of well known light quarks (or even antiquarks). The required weakness of the DM particle interactions is guaranteed by a small geometrical factor of the composite objects with a large baryon charge rather than by a weak coupling constant of a new field. We argue that the interaction between hadronic matter and composite dark objects does not spoil the desired properties of the latter as cold matter. We also argue that such a scenario does not contradict to the current observational data. Rather, it has natural explanations of many observed data, such as ${\Omega }_{DM}/{\Omega }_B\sim 1$ or $511KeV$ line from the bulge of our galaxy. We also suggest that composite dark matter may modify the dynamics of structure formation in the central overdense regions of galaxies. We also present a number of other cosmological/astrophysical observations which indirectly support the novel concept of DM nature.

Final version to appear in PRD. Some clarifications are made as referees requested. Few references added

References in corpus (4)

• Excess of EGRET Galactic Gamma Ray Data interpreted as Dark Matter Annihilation
• Difficulties for Compact Composite Object Dark Matter
• Distribution of mass in galaxy cluster CL0024 and the particle mass of dark matter
• Is there a dichotomy in the Dark Matter as well as in the Baryonic Matter properties of ellipticals?

Cited by in corpus (10)

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• Dark Matter Candidates: A Ten-Point Test
• Diffuse cosmic gamma-rays at 1-20 MeV: A trace of the dark matter?
• Width of the 511 KeV Line from the Bulge of the Galaxy
• Difficulties for Compact Composite Object Dark Matter
• The observational legacy of preon stars - probing new physics beyond the LHC
• Charges on Strange Quark Nuggets in Space
• What happened to the Cosmological QCD Phase Transition?
• Some Aspects of New CDM Models and CDM Detection Methods