Holographic Cosmology

• Kostas Skenderis (University of Amsterdam)

Lattice Holographic Cosmology

• Matthew Mostert (University of Southampton)

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Lattice QCD

• James Richings (University of Southampton)

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Searches for NMSSM Signatures with Low Missing Transverse Energy at the LHC

• Alexander Titterton (University of Bristol (GB))

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 $b\bar{b}b\bar{b}$ + $E_{T}^{\text{miss}}$ final state we then explore the sensitivity of a current CMS $\alpha_{T}$-based general-purpose jets+$E_{T}^{\text{miss}}$ analysis to such scenarios with a view to developing novel search approaches in the near future.

Renormalisation group fixed points and physics at highest energies

• Andrew Bond (University of Sussex)

Some recent developments in the understanding of particle theories controlled by ultraviolet fixed points.

Dimension-8 operators in Higgs physics

• Jack Setford (University of Sussex)

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.

Dark Matter

• Stephen West (Royal Holloway, University of London)

Probing the nature of Dark Matter at the ILC

• Daniel Locke (University of Southampton)

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 corresponding to scalar and fermionic DM. The first of which is the inert higgs doublet model (I2HDM), which is a $Z_2$ symmetric Two Higgs Doublet Model, with the lightest neutral scalar being identified as D. The latter contains an SU(2) doublet of vector-like Dirac fermions, and an additional neutral singlet fermion. In this model, D is a mixture of neutral fermion singlet and doublet. For minimal fermionic DM, we perform an analysis of constraints of the parameter space, coming from DM relic density, DM direct detection, and collider. We propose a method to determine the mass of DM and distinguish its spin, in the process $$e^+e^- \to D^+D^- \to DDW^+W^-\ to DD (q\bar{q})(\ell\nu)$ with a signature dijet + $\mu$ (or $e$) + missing mass.

Fast simulations of dark matter structure formation with modified gravity and massive neutrinos.

• Bill Wright (Institute of Cosmology and Gravitation, University of Portsmouth)

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 enhancement of structure formation due to modified gravity and suppression of structure formation due to massive neutrinos can make it difficult to distinguish between $\Lambda$CDM and modified gravity in observables such as the matter power spectrum.

Leptogenesis and BSM physics

• Pasquale Di Bari (University of Southampton)

Dark Matter indirect detection at Neutrino Telescopes: a multi-messenger approach

• Marco Chianese (University of Southampton)

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Predicting the Right-Handed Neutrino Masses From the Littlest Seesaw and Leptogenesis

• Sam Rowley (University of Southampton)

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 right-handed neutrino masses from a four-parameter fit to the low energy neutrino parameters, also eventually taking into account leptogenesis.

Quantum diffusion during inflation and primordial black holes

• Chris Pattison (ICG)

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 fluctuations is well approximated by a Gaussian. If they are large, the PDF has a different profile with a longer tail and leads to constraints different from the ones usually derived.

Using infinite derivative gravity to resolve singularities

• James Edholm

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.

Conformal window of asymptotic safety

• Gustavo Medina Vazquez (University of Sussex)

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.

Interacting vacuum dark energy

• Natalie Hogg

The standard model of cosmology, LCDM, suffers from both theoretical and observational problems that motivate alternative theories of dark energy. One such class of theories are interacting dark energy models. In my talk, I will give an overview of the problems with LCDM and discuss the interacting vacuum scenario, in which the time-varying vacuum energy is allowed to interact with dark matter. I will explain how this interaction can be reconstructed from and constrained by observational data and present some preliminary results.

Testing gravity with black holes and gravitational waves

• Helvi Witek

Conformally Coupled General Relativity

• Boris Latosh (University of Sussex)

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 performed with the use of reparametrization-invariant time and ADM foliation techniques. Basic quantum features of the models are discussed.

Rapid response gravitational wave follow-up with the PIRATE robotic telescope

• Dean Roberts

In the last two years since LIGO discovered the first gravitational waves, the field of gravitational wave astronomy has advanced rapidly. In the last observing run (O2) LIGO detected two more binary black hole mergers and with the help of Virgo, was also able to detect gravitational waves from a binary neutron star merger. This event was a landmark discovery because in addition to gravitational waves there was an electromagnetic (EM) counterpart discovered less than 12 hours later, which turned out to be the first in ~250 EM observations that followed, making this the most widely observed astronomical event in history. The large majority of these observations were performed by ground based optical telescopes, and it was these telescopes that have performed similar tasks in every other LIGO alert in O2; by searching the night sky for an optical counterpart to the gravitational wave signals. The PIRATE robotic telescope, owned by The Open University but located in Tenerife, took part in some of these follow-up searches and was able to utilize its robotic nature to perform rapid follow-up observations as soon as an alert was received.

Semi-empirical techniques to unveil the properties of both galaxies and their host dark matter halos

• Francesco Shankar

Neutrinoless Double Beta Decay and the Baryon Asymmetry of the Universe

• Frank Deppisch (University College London)

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 asymmetry in the lepton number in the early universe. Combined with SM sphaleron transitions, this would render many baryogenesis mechanisms at higher scales ineffective. I will highlight potential caveats to this argument, and the role of high energy colliders.

Gravitational Waves and Compact Binaries

• Christopher Berry

Graviataional Waves from Phase Transitions in the Early Universe

• Mark Hindmarsh (University of Sussex)