## Project

Black holes constitute one of the most stimulating topics in contemporary physics. My project **Quantum Singularities in Holographic Models** strives to
answer key questions concerning the nature of quantum singularities: what is the **structure of the Hilbert space**
describing quantum black holes? What is a relation between black holes and cosmologies? What
can **cosmology** tell us about black holes and vice versa? In particular, what can we learn about a relation
between **AdS/CFT** and **dS/CFT**? What is the **non-local interaction** between degrees of freedom on both sides
of the horizon and can we measure it in nature?

## Principal investigator

**Dr. Adam Bzowski**

Faculty of Physics, Institute for Theoretical Physics

ul. Pasteura 5, 02-093 Warszawa, Poland

email: abzowski at fuw.edu.pl

tel: +48 22 55 32808

office: 4.08

## Results

**Adam Bzowski,***Breaking the spell of the tensor product*, arXiv: 2104.06425

In this and the upcoming paper I argue that the Hilbert space of excitations on top of a wormhole does not factorize into the tensor product of the boundary Hilbert spaces. From the point of view of semiclassical physics, the decrease in the number of states is perceived as an emergent, non-local interaction stabilizing the wormhole. This presents new possibilities for models of radiating black holes and raises questions about results established under the spell of the tensor product. This picture shows a wormhole with information transferred from one boundary to the opposite one.

**Adam Bzowski, Paul McFadden, Kostas Skenderis,***A handbook of holographic 4-point functions*, arXiv: 2207.02872

In this paper I derive exact formulas for a number of scattering amplitudes taking place in anti-de Sitter spacetime. The goal is to use the derived results in order to provide specific and measurable predictions in cosmology. Indeed, the proposal known as

**holographic cosmology**allows one to relate anti-de Sitter amplitudes to cosmological correlation functions. These, in turn, are measurable quantities in the sky and provide us with information about the far past of our Universe. This picture shows two types of 4-point amplitudes calculated in the paper.

## Funding

The investigations are made possible by the NCN POLS grant and financed by the Norwegian Financial Mechanism 2014-2021. The project will take 2 years to complete: October 2021 - October 2023.