This thesis covers several theoretical aspects of WIMP (weakly interacting massive particles) dark matter searches, with a particular emphasis on colliders. It mainly focuses on the use of effective field theories as a tool for Large Hadron Collider (LHC) searches, discussing in detail the issue of their validity, and on simplified dark matter models, which are receiving a growing attention from the physics community. It highlights the theoretical consistency of simplified models, which is essential in order to correctly exploit their potential and for them to be a common reference when comparing results from different experiments. This thesis is of interest to researchers (both theorists and experimentalists) in the field of dark matter searches, and offers a comprehensive introduction to dark matter and to WIMP searches for students and non-experts.

I explore the hypothesis that dark matter is composed of Weakly Interacting Massive Particles, as motivated by various theories which solve the gauge hierarchy problem in the Standard Model of particle physics, and the interplay between various methods which can be sensitive to the presence of such a new particle. I present a model-independent parametrization of dark matter interactions and derive bounds on the various possible interactions from hadron collider studies sensitive to the presence of dark matter as well as from searches for new spectral lines in cosmic gamma rays, comparing the bounds from those two searches to those from direct detection experiments. I find that colliders provide the most strenuous constraints on spin-dependent scattering of dark matter, and that collider and indirect searches are highly complementary with direct detection searches, allowing derivations of the nature of dark matter interactions when a discovery does take place. I also present an exploration of how robust these collider bounds are to corrections from the presence of additional, related particles in the spectrum of new physics. As long as the additional, mediating particles are heavy enough to resonantly produce the final state that is searched for at colliders I find that the bounds from the effective theory are sound.

The 'WIMP miracle' for the relic abundance of thermal dark matter motivates weak scale dark matter with renormalizable couplings to standard model particles. This work examines minimal models with such couplings that explain dark matter as a thermal relic. The models contain a singlet dark matter particle with cubic renormalizable couplings between standard model particles and `partner' particles with the same gauge quantum numbers as the standard model particle. The dark matter has spin 0, 1/2, or 1, and may or may not be its own antiparticle. Each model has 3 parameters: the masses of the dark matter and standard model partners, and the cubic coupling. Requiring the correct relic abundance gives a 2-dimensional parameter space where collider and direct detection constraints can be directly compared. This work focuses on the case of dark matter interactions with quarks and leptons.For quark models, collider and direct detection searches are remarkably complementary. Direct detection limits for the cases where the dark matter is not its own antiparticle require dark matter masses to be in the multi-TeV range, where they are extremely difficult to probe in collider experiments. The models where dark matter is its own antiparticle are strongly constrained by collider searches for monojet and jets +MET signals. These models are constrained by direct detection mainly near the limit where the dark matter and partner masses are nearly degenerate, where collider searches become more difficult.In the lepton case, the most sensitive collider probe is the search for leptons + MET, while the most sensitive direct detection channel is scattering off nuclei arising from loop diagrams. Here too collider and direct detection searches are highly complementary: colliders give the only meaningful constraint when dark matter is its own antiparticle, while direct detection is generally more sensitive if the dark matter is not its own antiparticle.

The Early Universe has become the standard reference on forefront topics in cosmology, particularly to the early history of the Universe. Subjects covered include primordial nubleosynthesis, baryogenesis, phases transitions, inflation, dark matter, and galaxy formation, relics such as axions, neutrinos and monopoles, and speculations about the Universe at the Planck time. The book includes more than ninety figures as well as a five-page update discussing recent developments such as the COBE results.

Dark matter is a frequently discussed topic in contemporary particle physics. Written strictly in the language of particle physics and quantum field theory, these course-based lecture notes focus on a set of standard calculations that students need in order to understand weakly interacting dark matter candidates. After introducing some general features of these dark matter agents and their main competitors, the Higgs portal scalar and supersymmetric neutralinos are introduced as our default models. In turn, this serves as a basis for exploring four experimental aspects: the dark matter relic density extracted from the cosmic microwave background; indirect detection including the Fermi galactic center excess; direct detection; and collider searches. Alternative approaches, like an effective theory of dark matter and simplified models, naturally follow from the discussions of these four experimental directions.

Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.

Particle dark matter: the name of the game -- The thermal relic paradigm: zeroth-order lessons from cosmology -- The thermal relic paradigm: a closer look -- The art of WIMP direct detection -- Indirect dark matter searches -- Searching for dark matter with particle colliders -- Axions and axion-like particles as dark matter -- Sterile neutrinos as dark matter particles -- Bestiarium: a short, biased compendium of notable dark matter particle candidates and models