We examine scenarios in the Next to Minimal Supersymmetric Standard Model where pair-produced squarks and gluinos decay via two cascades, each ending in a stable neutralino LSP and a standard model Higgs with the mass gaps in the decay such that the Missing Transverse Energy is very small. Performing two-dimensional parameter scans and focusing on the hadronic h→$b\bar{b}$ decay giving a...
Some recent developments in the understanding of particle theories controlled by ultraviolet fixed points.
I will describe the process by which one can derive the full set of dimension-8 bosonic operators involving Higgses and gauge bosons. I will then discuss the implications of these operators on current measurements and bounds on dimension-6 Wilson coefficients.
We analyse the potential of the proposed international linear collider to detect Dark Matter (DM) and determine its properties. In many models stability of Dark Matter particles D is ensured by conservation of a new quantum number referred to as D-parity. Our models also contain charged D-odd particles $D^{\pm}$ with the same spin as D. In this work, we study two minimal consistent models...
I will briefly introduce the need for fast, approximate tools for cosmological simulations of dark matter structure formation, before talking about how we have implemented both modified gravity and massive neutrinos into the fast, approximate simulation tool $\tt{COLA}$.
I will present results produced by this extended version of $\tt{COLA}$ and explain how a potential degeneracy between the...
The Littlest Seesaw model based on two right-handed neutrinos with constrained Yukawa couplings provides a highly predictive description of neutrino masses and PMNS mixing parameters. If realised at high energies there will be renormalisation group corrections to the low energy predictions, which depend on the right-handed neutrino masses. We perform a $\chi^2$ analysis to determine the...
I will explain how primordial black holes can form from perturbations seeded during inflation and how their abundance can be calculated in the framework of stochastic inflation. This formalism incorporates quantum backreaction of the small-wavelength fluctuations on the large distances dynamics of the Universe. If quantum corrections are small, the probability distribution of density...
Infinite derivative gravity adds terms which make gravity weaker at short distances, allowing us the possiblity of avoiding the singularities which plague General Relativity. I will discuss both linearised perturbations to the flat metric and bouncing FRW cosmologies.
The conformal window of a general class of gauge theories featuring a weakly coupled UV fixed point is investigated at next-to-next-to-leading order and found to lie completely within the domain of perturbation theory. Constraints are derived in various approximations, finding that vacuum instability yields the tightest constraint at NNLO.
Gravity model developed in the series of papers Grav.Cosmol. 15 (2009) 199-212; Phys.Lett. B691 (2010) 230-233; Gen.Rel.Grav. 44 (2012) 2745-2783 is revisited. Model is based on Ogievetsky theorem that specifies structure of general coordinate transformation group. The theorem is implemented in the context of Noether theorem with the use of nonlinear representation technique. Quantization is...
I will discuss the impact of the observation of neutrinoless double beta decay on the washout of lepton number in the early universe. Neutrinoless double beta decay can be triggered by a large number of mechanisms that can be encoded in terms of SM effective operators which violate lepton number. Such operators, or the underlying UV processes would also be responsible for the washout of an...
Large areas of galaxy clusters, voids and filaments make up the cosmic web. An important realisation was that the distribution of galaxies does not exactly trace the total matter density field (dark matter plus baryonic matter) of the cosmic web. The linear bias (overdensity of baryonic matter to all matter) of galaxy populations informs us about their environmental properties, which can be a...
