Through theory and observations, it is well established that the universe undergoes accelerated expansion in its history. This accelerated expansion takes place in two different epochs. The first of these is the early epoch of inflation and the second is the current epoch of dark energy domination. Although methods of General Relativity, which is the classical theory of gravity, and Quantum Field Theory, which addresses matter interactions at quantum scales, have guided much of our understanding of the universe, they cannot fully address these epochs of accelerated expansion. In this project the objective is to identify the cosmological degrees of freedom that have a crucial role during inflation and dark energy. It proposes to achieve this goal by studying the ideal case of a spacetime that gives accelerated expansion, using recent methods in holography in order to (i) identify specific deformations from the ideal case that give rise to the cosmological degrees of freedom during inflation and dark energy separately; (ii) explore the generality of these deformations and their cosmological consequences using methods of renormalization group flows; (iii) address deformations in the context of time dependent and space dependent evolution separately to further improve the understanding on the nature of cosmological degrees of freedom. This interdisciplinary project proposes to use the principle of holography from String Theory which can open up a new way of studying cosmological perturbations, especially in the context of dark energy. By focusing on cosmological spacetimes, it will also address the validity of holography in new settings.

The origin of the accelerated expansion of the Universe remains elusive. The so-called Dark Energy might be a manifestation of modified gravity at very large scales. While near-future observatories will improve the current bounds on such a possibility, they will not likely be conclusive as to its nature. An opportunity arises from the study of modifications of gravity at shorter scales, specifically around compact objects like black holes and neutron stars, recently made possible through gravitational-wave observations. This project aims to dramatically improve the constraints on cosmological modifications of gravity by means of an interdisciplinary approach involving tools from High Energy Physics, and both astrophysical gravitational-wave and cosmological observations. Modified gravity dynamics at different scales can be described in a model-independent way as Effective Field Theories according to symmetry principles. Strong constraints will come from a combined theoretical and phenomenological study within this framework. Both analytical and numerical tools will be developed and employed to qualitatively and quantitatively compute the expected signatures on gravitational-wave astrophysics, allowing to hold these models against observations. The constraints will then be translated to the cosmological modifications of gravity, drawing novel conclusions as to which theories can consistently explain Dark Energy while satisfying bounds across a large range of scales. Ultimately, this project will foster the collaboration among the High Energy Physics, Cosmology and Gravitational-Wave Astrophysics communities, enabling a much faster and efficient progress in the field of modified gravity in general. This includes a more focused use of the available computational resources for time-consuming resource-intensive tasks. The multifaceted training and support received during the action and the competences acquired are aimed at the career development of the fellow.

Magnetic shape memory alloys (MSMAs) are smart materials which exhibit large shape changes in magnetic field. Novel functionalities of MSMAs, such as mechanically-induced demagnetization, originating from the enlarged magnetic hysteresis (MAH), have recently been introduced by the fellow. The finding opens a new topic in the field and extends significantly the application potential of MSMAs. Large scientific and commercial impact is expected if the research is further pursued. The objective of this project is to build comprehensive understanding of the novel functionalities of MSMAs resulting from the enlarged MAH and to confirm them experimentally. First, we will identify the causes of enlarged MAH in Ni-Mn-Ga-(B) alloys and explain the physical mechanisms underlying the novel functionalities. The acquired knowledge will be used to produce new MSMAs with strengthened novel functionalities. These new alloys will be characterized and used in demo applications built within the project to explain and merchandise the advantages of novel functionalities to industrial community and general public. The project outputs will advance the fields of magnetism, martensite, and MSMAs by explaining the novel functionality paradigm based on interaction of hard ferromagnetic and ferroelastic microstructures. The outputs will be also of practical value, shifting the MSMAs towards new types of practical applications. The Host Institute will enable the fellow an access to unique instrumentation and expertise in magnetism and alloy production while simultaneously will integrate the fellow as a senior researcher. In return, the fellow will bring his unique combined industrial and academic experience in the field of MSMAs as well as new collaborators from Finland, Poland, Germany, and USA. The project boosts the fellow's research skills in experimental physics and initiates his independent research career in the Czech Republic.

The most common ionizing radiation detectors using inorganic solid scintillators do not currently enable the technological progress in the fields of high-energy particles detection and medical diagnosis (such as in time-of-flight PET tomography), where high light yield and fast timing capabilities are needed. Nanoparticles can be exploited as scintillators to overcome these limits due to the possibility to control and modify their structural and luminescence properties. Moreover, nanoparticles can be embedded in polymers for the fabrication of nanocomposites with high optical transparency. The main goal of the project is to develop advanced hafnium oxide nanocomposite scintillators with time response in nanoseconds, while exploiting the hafnia quality to efficiently stop the ionizing radiation. In order to reach the project goal, the radioluminescence properties of inorganic hafnia nanoparticles will be optimized by defects engineering and doping strategies. The hafnia surfaces will be decorated with highly fluorescent organic dyes and the radioluminescence of nanoparticles will sensitize the dye emission. These hybrid nanoscintillators will be embedded in a polymer matrix in order to fabricate low cost, flexible and scalable nanocomposite scintillators with optimized luminescence efficiency and fast time response. The project is at the forefront of the progress in high-energy physics experiments to minimize the photons losses at high count rates, and meets the urgent demands of medical imaging techniques to gain high quality images. The results of the proposed research will represent a fundamental step forward towards significant advances in technologies for ionizing radiation detection as well as reinforce the position of the European scintillation community worldwide.

Despite numerous studies of liquid water, its molecular structure has not yet been fully resolved and understanding of its specific properties remains limited. Recent experimental and theoretical studies have shown that interfacial water formed on surfaces of various synthetic materials tends to exhibit long-range order. Specifically, water exhibits unique physicochemical properties next to the super hydrophilic Nafion surface such as the exclusion of solutes and microspheres, higher refractive index and viscosity, absorption at 270 nm, and charge separation susceptible to incident electromagnetic energy. Ordered layers of water molecules have been also found next to biomolecules like proteins or DNA suggesting a dynamic interaction between matter and aqueous media based on hydrogen bonding or other electrostatic interactions. Simulation studies have also shown that water adjacent to graphene surfaces could build an extensive hydrogen bond network suggesting that water might be involved in the p–p interactions between aromatic groups. In the ATTIC project, the water layer built in the vicinity of various surfaces will be extensively investigated at a molecular level by employing dielectric, THZ and Raman spectroscopic techniques. The spectroscopic studies will be initially focused on Nafion and other hydrophilic surfaces and subsequently, the interactions of water with the aromatic groups of graphene will be explored. The last part of the project includes spectroscopic studies next to orthogonally synthesized styrene-based polymers that bear different functionalization to explore how alterations in the electronic density of aromatic groups affect the water dynamics and the overall self-assembly state of polymers in water. This project aims to bridge the gap between diverse experimental and theoretical works on unique water properties and to pave the way for the development of innovative water-based technologies.