Talks

Polyaromatic hydrocarbons (PAHs) such as acenes have long been studied due to its interesting optical properties and low singlet triplet gaps. Earlier studies have already noticed that use of complete valence active space is imperative to the understanding of its qualitative and quantitative properties. Since complete active space based methods cannot be applied to such large active spaces, we have used density matrix renormalization group (DMRG) based approaches. Further small modification to the PAH topology shows interesting new phases of behaviour in its optical gaps. We have understood the effect of these effects based on spin frustration due to the presence of odd membered rings. In this talk, I will discuss these observations from molecular and model Hamiltonian perspectives.Further developments based on artificial neural network based configuration interaction for strongly correlated systems will also be discussed.5  The similarities between the ANNs and the MPS wavefunctions will be leveraged for 2D systems.

Zoom link:  https://pitp.zoom.us/j/92159136836?pwd=ZFJBcXZ3R3czSUcxcThOci9ueStBZz09

Effective field theory analysis are inadequate to describe the evolution of the very early universe. I will describe an approach to obtain emergent time, emergent space, an emergent metric and an emergent early universe cosmology starting from the BFSS matrix model, a proposed non-perturbative definition of superstring theory. In this approach there is no cosmological constant problem.

Abstract: The universe presents itself as a grand laboratory to explore and investigate a range of physical phenomena. High-energy cosmic messengers serve as unique tools to unravel some of the most energetic processes beyond the capabilities of current  human-made particle accelerators. These messengers are not only instrumental in providing cosmological insights by probing the medium they traverse, but also hold the potential to detect Planck-scale effects that accumulate over long distances.  In this talk, I will focus on the theory of cosmological particle propagation. I will then describe how they can be used to search for the elusive dark matter, in particular axion-like particles (ALPs). Finally, I will discuss some of the ways in which cosmic particles have been used to investigate quantum gravity phenomena at high and ultra-high energies.

What is quantum? Something very advanced... Perhaps something to do with time travel? And definitely linked to computing somehow! Is it spooky? Is it revolutionary? Perhaps it's time to join Ant-Man in being sucked down into the Quantum Realm? This workshop will be dedicated to exploring how the public currently perceives and relates to quantum. We will discuss findings from current research on quantum education & outreach and share our own experiences in communicating about quantum outside of our research bubble. We will ask the question of "What does it mean to develop quantum for the public good?". Finally, we will make the case for why the public should be involved in answering that question: By playing an active role in determining the societal values that guide technical research. In contrast to AI ethics, that process can happen now, while we are in the early phases of realizing quantum technology.

"After reviewing some key hints and puzzles from the early universe, I will introduce recent joint work with Neil Turok suggesting a rigid and predictive new approach to addressing them. Our universe seems to be dominated by radiation at early times, and positive vacuum energy at late times. Taking the symmetry and analyticity properties of such a spacetime seriously leads to a new formula for the gravitational entropy of our universe, and a picture in which the Big Bang may be regarded as a kind of mirror. I will explain how this line of thought suggests new explanations for a number of observed properties of the universe, including: its homogeneity, isotropy and flatness; the arrow of time (i.e. the fact that entropy increases *away* from the bang); several properties of the primordial perturbations; the nature of dark matter (which, in this picture, is a right-handed neutrino, radiated from the early universe like Hawking radiation from a black hole); the origin of the primordial perturbations; and even the existence of three generations of standard model fermions. I will discuss some observational predictions that will be tested in the coming decade, and some key open questions."

I will review recent work on accelerating spacetimes in 3D, explaining how acceleration manifests for point particles and BTZ black holes, as well as a novel BTZ-like solution in a disconnect region of parameter space. I will also discuss some holographic aspects of the solutions.

I will give an overview of how the Event Horizon Telescope achieves its horizon scale science and what's to come. I will also review selected recent results from the Event Horizon Telescope both on Sgr A* and refined analysis of M87*. A focus will be on analysis aspects that are relevant for any theory / model building along with a few examples. The presentation aims to provide key conceptual aspects relevant to gravity experts who are new to VLBI.

To make progress in developing a quantum theory of gravity, we need to connect candidate theories to observations. I will review ideas on connecting quantum gravity to observations in particle physics, to searches for dark matter and to observations of black holes, in particular with the (next-generation) Event Horizon Telescope.