Conveners
Day 1: From Cosmological Bootstrap to the Wave Function of the Universe
- Masahide Yamaguchi (IBS CTPU-CGA)
Day 1: Dark Sectors and Astrophysical Probes of Dark Matter
- Zhong-Zhi Xianyu (Tsinghua University)
Day 1: Gravitational-Wave Probes of Compact Objects and Early-Universe Perturbations
- Sam Wong (City University of Hong Kong)
We develop a new bootstrap strategy for cosmological correlators at loop level, which we call spectral dispersion. It is based on two conceptual observations that a correlator can be recovered from its on-shell data, also known as nonlocal signals, by analyticity up to local counterterms, and that the on-shell data for a loop process take the form of a discrete sum over quasinormal modes....
Cosmological correlators are fundamental observables of early universe cosmology and the main targets of cosmological surveys. Despite their importance, computing them remains notoriously hard. In this talk, the speaker will show how to bootstrap several classes of correlators tied to signatures of observational interest, including large non-Gaussianities, primordial features, and parity violation.
Our understanding of the primordial Universe largely depends on the information from spatial correlations of cosmic-scale matter distributions. Recently, the advances of the “cosmological bootstrap” program offers new perspectives and powerful tools to study these cosmological correlators. In this talk, I will review the exciting developments along this direction, with a focus on the...
I will describe the landscape of a dark sector with (excited) dark matter and various force mediators controlled by dark gauge symmetry. Then I will discuss the following topics one by one: (i) Why do we have to consider the dark Higgs boson? (ii) Galactic center gamma-ray excess with dark Higgs (iii) WIMP scenario resurrected with dark Higgs boson (iv) 511 keV gamma ray excess (v) Higgs...
We discuss a two-component dark matter model in which one component, heavier dark matter, annihilates into a lighter dark matter. The lighter dark matter is expected to generate detectable signals in detectors due to its enhanced momentum, enabling direct detection even for MeV-scale dark matter. We investigate the effectiveness of directional direct detections, especially the nuclear emulsion...
The dark matter surrounding black hole would form dense dark environment, studying the imprint of dark matter on the observational signals from black hole via accretions and dynamical friction could be a dark matter probe. In this talk I am going to talk about how to study the nature of dark matter from radio, optics and gravitational wave channels. With these studies, black hole would be a...
Extreme mass ratio inspirals (EMRIs) composed of a stellar-mass object inspiraling into a supermassive black hole (SMBH), emitting GWs in the milli-Hertz band, are the most promising GW sources for space-based observatories. The rich information about the spacetime geometry surrounding the SMBH is encoded in the GWs, making EMRIs an excellent source for studying black hole physics like the...
A strongly self-interacting component of asymmetric dark matter (DM) particles can form compact dark stars (DSs). These objects have a broad spectrum of masses and radii, with distinct evolution histories from both neutron stars and black holes (BHs). These differences allow a population of DSs to contribute significantly to the astrophysical merger rate in unique and discernible ways....
With the advent of third-generation gravitational-wave detectors, it has become crucial to extend analytical frameworks used to model waveforms from compact binary systems to alternative theories of gravity. In this talk, I will present recent results on radiation-reaction effects in a class of scalar–tensor theories. Using the post-Newtonian multipolar post-Minkowskian (PN–MPM) formalism, we...
The statistical properties of the curvature perturbation on superhorizon scales during inflation are of significant phenomenological interest, with implications ranging from cosmic microwave background (CMB) observations to primordial black hole (PBH) formation and induced gravitational waves. In this talk, I will present and compare different techniques for computing these properties: the...
