In this paper, we construct the annihilation and creation operators for massive scalar particles in 1 + 3 dimensional de Sitter space using Berezin’s integral quantization method. We begin by demonstrating that the phase space of a massive scalar particle in this curved spacetime is isomorphic to the complex four-dimensional sphere $$S_{\mathcal {C}}^3$$ . Each point on this complex sphere is associated with a vector (or coherent state) in a corresponding Hilbert subspace. We emphasize the intrinsically four-dimensional nature of the annihilation and creation operators and examine their connection to the infinitesimal generators of time translations and Lorentz boosts.

Iran

A. Rabeie

Quantum field theory on 1 + 3-de Sitter space: annihilation and creation operators

<p>We analyze the computation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi></math>-point correlation functions in de Sitter spacetime, including loop corrections, using the wave function of the universe approach. This method consists of two stages employing distinct Feynman rules. First, one must compute the wave-function coefficients using interactions as vertices. Then, in the second stage, one computes correlation functions using wave-function coefficients as vertices. For massless fields, loop corrections in the first stage are free of infrared (IR) divergences, which leads to the question of how this matches the well-known IR behavior of correlators obtained via other methods. By considering a scalar field with an arbitrary potential, we compute <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi></math>-point correlation functions to first order in the potential but to all orders in loops. We find that although loop integrals in the first stage are indeed IR convergent, the second procedure reintroduces the IR divergence. We discuss how this induces renormalization of the interaction potential such that the final result combining both steps exactly matches the form of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi></math>-point functions previously calculated with other methods.</p>

Chile

Javier Huenupi

United States

Ellie Hughes

Gonzalo A. Palma

Thailand

Spyros Sypsas

Note on loop resummation in de Sitter spacetime with the wave function of the universe approach

It is known that the double-scaled SYK model (DSSYK) reduces to JT gravity with a negative cosmological constant by zooming in on the lower edge $\textit{E}$ = – $\textit{E}$ of the spectrum. We find that the de Sitter JT gravity (i.e. JT gravity with a positive cosmological constant) is reproduced from DSSYK by taking a scaling limit around the upper edge $\textit{E}$ = $\textit{E}$ of the spectrum. We also argue that the appearance of de Sitter JT gravity is consistent with the behavior of the classical solution of the sine dilaton gravity.

Japan

Kazumi Okuyama

de Sitter JT gravity from double-scaled SYK

We study quantum corrections to the Euclidean path integral of charged and static four-dimensional de Sitter (dS ) black holes near extremality. These black holes admit three different extremal limits (Cold, Nariai and Ultracold) which exhibit AdS × $\textit{S}$ , dS × $\textit{S}$ and Mink × $\textit{S}$ near horizon geometries, respectively. The one-loop correction to the gravitational path integral in the near horizon geometry is plagued by infrared divergencies due to the presence of tensor, vector and gauge zero modes. Inspired by the analysis of black holes in flat space, we regulate these divergences by introducing a small temperature correction in the Cold and Nariai background geometries. In the Cold case, we find a contribution from the gauge modes which is not present in previous work in asymptotically flat spacetimes. Several issues concerning the Nariai case, including the presence of negative norm states and negative eigenvalues, are discussed, together with problems faced when trying to apply this procedure to the Ultracold solution.

United Kingdom

Matthew Blacker

Alejandra Castro

Sweden

Watse Sybesma

Italy

Chiara Toldo

Quantum corrections to the path integral of near extremal de Sitter black holes

A technique to build perturbative series for the spectator field’s correlation functions in de Sitter space through the Fokker-Planck equation is proposed. We derive from the first-order differential equation the iterative integral relation for equal- and multi-time correlation functions. With an appropriate integration, the obtained two-point and four-point correlation functions are in agreement with quantum field theory’s ones.

Alexander Kamenshchik

Polina Petriakova

From the Fokker-Planck equation to perturbative QFT’s results in de Sitter space

We study the stress-energy tensor of a massless, conformally-coupled, quantum scalar field in a rigidly-rotating thermal state on three- and four-dimensional anti-de Sitter space-time. We first find the stress-energy tensor using relativistic kinetic theory, modelling the field as a thermal gas of massless bosons. We then compute the renormalized stress-energy tensor of the scalar field in quantum field theory and compare it with that resulting from relativistic kinetic theory.

Jacob C. Thompson

Elizabeth Winstanley

Quantum effects in rotating thermal states on anti-de Sitter space-time

This paper seeks to explore the holographic optical appearance of an anti-de Sitter (AdS) black hole with higher-derivative corrections in the presence of a string cloud, drawing on the AdS/conformal field theory (CFT) correspondence and wave optics. We introduce a Gaussian wave source that oscillates at the AdS boundary and propagates through the bulk. The resulting response function is then analyzed using an imaging system to study the optical properties of the black hole. Depending on the observer’s position and variations in system parameters, the resulting holographic image takes on different forms, including a well-defined Einstein ring, deformed luminous patterns, or isolated bright spots. Notably, when the observer is positioned at the north pole, the image consistently features a bright ring at the photon sphere, encircled by concentric stripes. Our findings reveal a strong correlation between the Einstein ring’s location and the photon sphere radius predicted by geometric optics, reinforcing the connection between wave optics and gravitational lensing. Additionally, we examine the influence of higher-derivative corrections and string cloud parameters on the observed optical features.

India

Abhishek Baruah

Bidyut Hazarika

Prabwal Phukon

Holographic Einstein Rings of anti-de Sitter Black Holes with Higher-Derivative Corrections in Presence of String Cloud

This paper investigates basic properties of the de Sitter static patch using simple two-point functions in the probe approximation. We find that de Sitter equilibrates in a superdiffusive manner, unlike most physical systems which equilibrate diffusively. We also examine the scrambling time. In de Sitter, the two-point functions of free fields do not decay for sometime because quanta can reflect off the pole of the static patch. This suggests a minimum scrambling time of the order log(1$\textit{/G}$ ), even for perturbations introduced on the stretched horizon, indicating fast scrambling inside de Sitter static patch. We also discuss the interplay between thermodynamic temperature and inverse correlation time, sometimes called “tomperature.”

Alexey Milekhin

Jiuci Xu

On scrambling, tomperature and superdiffusion in de Sitter space

We argue for the existence of bounds on the tensions of $\textit{p}$-branes in de Sitter space in terms of the Hubble rate and the strength of a class of Chern-Simons-like couplings. The world-volume couplings involve Abelian 1-form gauge fields in the bulk and possibly field strengths intrinsic to the brane. In many cases these couplings are the D-brane Chern-Simons terms present in string theory, while in other cases they are the interactions of axion domain walls with U(1) fields. Our arguments use the same logic and assumptions as the recent Festina Lente proposal (thus utilizing the properties of Nariai de Sitter black holes) and generalize it to extended objects, thereby providing a bottom-up set of constraints independent of any particular UV completion. We compare these bounds to the properties of (wrapped) D-branes in Type II string theory in the weak coupling limit, under the assumption that these properties are not modified significantly in de Sitter constructions. We find that all constraints are satisfied by D-branes, providing further evidence for the Festina Lente conjecture. For the particular case of 2-branes with Chern-Simons interactions we obtain a bound, which however can be evaded if the theory contains a light axion. Similarly, we find the bounds do not apply to axion domain walls due to the presence of the axion.

Saquib Hassan

Georges Obied

John March-Russell

De Sitter space constraints on brane tensions and couplings

<p>We develop the pole-skipping structure in de Sitter (dS) spacetime and find that their leading frequencies satisfy the relation <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ω</mi><mrow><mi>d</mi><mi>S</mi></mrow></msub><mo>=</mo><mi>i</mi><mn>2</mn><mi>π</mi><msub><mi>T</mi><mrow><mi>d</mi><mi>S</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mi>s</mi><mo stretchy="false">)</mo></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>d</mi><mi>S</mi></mrow></msub><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn><mi>π</mi><mi>L</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math> denotes spin. In the two-dimensional dS spacetime, the pole-skipping points near the cosmic horizon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>r</mi><mo>=</mo><mi>L</mi></math> for the scalar field of spin 0 and the fermionic field of spin <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mfrac><mn>1</mn><mn>2</mn></mfrac></math> correspond one to one with those in the classical limit as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi><mo stretchy="false">→</mo><mn>0</mn></math> in double-scaled Sachdev-Ye-Kitaev model when the temperature is infinite (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mrow><mi>DSSYK</mi></mrow><mi>∞</mi></msub></math>). This provides a numerical correspondence between quantum gravity in the static patch of two-dimensional dS spacetime and a one-dimensional quantum system, which we consider as a realization of the DS/dS correspondence.</p>

China

Haiming Yuan

Xian-Hui Ge

South Korea

Keun-Young Kim

Pole skipping in two-dimensional de Sitter spacetime and double-scaled SYK model