Asimina Arvanitaki

Searching for dilaton dark matter with atomic clocks

We propose an experiment to search for ultralight scalar dark matter (DM) with dilatonic interactions. Such couplings can arise for the dilaton as well as for moduli and axion-like particles in the presence of

Astrophysical probes of unification

CP

The Last Vestiges of Naturalness

violation. Ultralight dilaton DM acts as a background field that can cause tiny but coherent oscillations in Standard Model parameters such as the fine-structure constant and the proton-electron mass ratio. These minute variations can be detected through precise frequency comparisons of atomic clocks. Our experiment extends current searches for drifts in fundamental constants to the well-motivated high-frequency regime. Our proposed setups can probe scalars lighter than

Discovering the QCD Axion with Black Holes and Gravitational Waves

1{0}^{\ensuremath{-}15}\text{ }\text{ }\mathrm{eV}

Resonantly Detecting Axion-Mediated Forces with Nuclear Magnetic Resonance

with a discovery potential of dilatonic couplings as weak as

Limits on Split Supersymmetry from Gluino Cosmology

1{0}^{\ensuremath{-}11}

Detecting high-frequency gravitational waves with optically levitated sensors

times the strength of gravity, improving current equivalence principle bounds by up to 8 orders of magnitude. We point out potential

Decaying Dark Matter As a Probe of Unification And TeV Spectroscopy

1{0}^{4}

One loop predictions of the finely tuned supersymmetric standard model

sensitivity enhancements with future optical and nuclear clocks, as well as possible signatures in gravitational-wave detectors. Finally, we discuss cosmological constraints and astrophysical hints of ultralight scalar DM, and show they are complimentary to and compatible with the parameter range accessible to our proposed laboratory experiments.

Black Hole Mergers and the QCD Axion at Advanced LIGO

Traditional ideas for testing unification involve searching for the decay of the proton and its branching modes. We point out that several astrophysical experiments are now reaching sensitivities that allow them to explore supersymmetric unified theories. In these theories the electroweak-mass dark matter particle can decay, just like the proton, through dimension 6 operators with lifetime {approx}10{sup 26} s. Interestingly, this time scale is now being investigated in several experiments including ATIC, PAMELA, HESS, and Fermi. Positive evidence for such decays may be opening our first direct window to physics at the supersymmetric unification scale of M{sub GUT}{approx}10{sup 16} GeV, as well as the TeV scale. Moreover, in the same supersymmetric unified theories, dimension 5 operators can lead a weak-scale superparticle to decay with a lifetime of {approx}100 s. Such decays are recorded by a change in the primordial light element abundances and may well explain the present discord between the measured Li abundances and standard big bang nucleosynthesis, opening another window to unification. These theories make concrete predictions for the spectrum and signatures at the LHC as well as Fermi.