Dark Matter and The Anthropic Principle

Abstract

We evaluate the problem of galaxy formation in the landscape approach to phenomenology of the axion sector. With other parameters of standard LambdaCDM cosmology held fixed, the density of cold dark matter is bounded below relative to the density of baryonic matter by the requirement that structure should form before the era of cosmological constant domination of the universe. Galaxies comparable to the Milky Way can only form if the ratio also satisfies an upper bound. The resulting constraint on the density of dark matter is too loose to select a low axion decay constant or small initial displacement angle on anthropic grounds.

17 pages, 1 figure

References in corpus (8)

• Type IIA Moduli Stabilization
• Observational Consequences of a Landscape
• Distributions of nonsupersymmetric flux vacua
• Spin, Accretion and the Cosmological Growth of Supermassive Black Holes
• A Dark Hydrogen Cloud in the Virgo Cluster
• A Model of Anthropic Reasoning, Addressing the Dark to Ordinary Matter Coincidence
• Statistics of String vacua
• A Dark Galaxy in the Virgo Cluster Imaged at 21-cm

Cited by in corpus (26)

• Dimensionless constants, cosmology and other dark matters
• Theory and Phenomenology of Planckian Interacting Massive Particles as Dark Matter
• Life at the Interface of Particle Physics and String Theory
• A Universe Without Weak Interactions
• Populating the Landscape: A Top Down Approach
• Primordial black holes in the curvaton model: possible connections to pulsar timing arrays and dark matter
• Hunting for super-heavy dark matter with the highest-energy cosmic rays
• Anthropic Explanation of the Dark Matter Abundance
• The Multiverse and Particle Physics
• The scale of gravity and the cosmological constant within a landscape
• Axions, Inflation and the Anthropic Principle
• Why is the Supersymmetry Breaking Scale Unnaturally High?
• Why Comparable? A Multiverse Explanation of the Dark Matter-Baryon Coincidence
• Hypercharged Dark Matter and Direct Detection as a Probe of Reheating
• Mass Hierarchy and Vacuum Energy
• Why three generations?
• Environmentally Selected WIMP Dark Matter with High-Scale Supersymmetry Breaking
• Dark Matter and Naturalness
• Is the magnitude of the Peccei-Quinn scale set by the landscape?
• High Scale SUSY Breaking From Topological Inflation
• Pure Gravity Mediation and Chaotic Inflation in Supergravity
• A Local Wheeler-DeWitt Measure for the String Landscape
• Baryon-to-Dark Matter Ratio from Random Angular Fields
• Lower limit on the gravitino mass in low-scale gauge mediation with $m_H\simeq 125$GeV
• Why $w\ne -1$? Anthropic Selection in a $\Lambda$ + Axion Dark Energy Model
• A Closer Look in the Mirror: Reflections on the Matter/Dark Matter Coincidence