Emerging Paradigms in Inflationary Cosmology

Inflation provides a leading framework for understanding the dynamics of the early Universe and the origin of primordial perturbations. Beyond the standard single-field slow-roll picture, current research explores warm and dissipative inflation, noncanonical and multifield dynamics, modified-gravity couplings, and other mechanisms that can leave distinctive primordial signatures. At the observational interface, increasingly precise CMB measurements, including the recent ACT DR6 release, provide new opportunities to test inflationary scenarios and extensions of the standard cosmological model. Additionally, the rapid growth of cosmological and gravitational-wave datasets is motivating data-driven approaches based on machine learning and simulation-based inference. These developments open complementary routes to model reconstruction, parameter inference, and the study of enhanced small-scale perturbations and their possible role in primordial black-hole formation.This Research Topic aims to connect advances in inflationary theory with emerging computational methods and observable consequences in early-Universe and gravitational-wave cosmology. The first goal is to examine how warm and cold inflation can be generalized through noncanonical kinetic structures, multifield dynamics, modified gravity, and new dissipation mechanisms, and how their predictions can be confronted with current observations. The second is to highlight scientifically grounded applications of artificial intelligence, machine learning, and simulation-based inference to cosmological and gravitational-wave data, including signal analysis, model emulation, parameter estimation, source-population studies, and cosmological inference. The third is to investigate how inflationary dynamics, including warm-inflationary dissipation, can enhance scalar perturbations on small scales and generate primordial black holes, together with associated scalar-induced gravitational-wave signals. This Research Topic seeks studies that connect theoretical mechanisms to quantitatively testable predictions and robust inference.We welcome Original Research, Review, Mini Review, Perspective, Hypothesis and Theory, Methods, and Technology and Code contributions.1. New inflationary dynamics and observational signaturesCold and warm inflation; noncanonical and pure k-inflationary models; multifield and constant-roll dynamics; primordial perturbations and non-Gaussianity; thermal fluctuations, dissipative dynamics, and the microphysical origins and phenomenology of dissipation in warm inflation; inflation in modified-gravity and nonminimal-coupling frameworks; and observational signatures and parameter constraints. Studies comparing inflationary models with current CMB and large-scale-structure observations, including analyses using recent ACT DR6 results, are particularly encouraged.2. Artificial intelligence, machine learning, and data-driven inflationary cosmologyAI and machine-learning methods for inflationary and gravitational-wave cosmology, including neural networks, deep and generative models, genetic algorithms, symbolic regression, simulation-based inference, fast emulators, primordial-spectrum reconstruction, inflationary-model reconstruction, and AI-assisted model discovery, model selection and parameter estimation, signal detection, source-population inference, multimessenger association, and standard-siren cosmology. Applications to CMB, large-scale structure, weak lensing, gravitational waves, and multimessenger datasets are welcome, as are scientifically validated approaches to high-dimensional inference, systematic effects, uncertainty quantification, and AI-assisted theory and model discovery.3. Inflationary production of primordial black holes and induced gravitational wavesInflationary mechanisms that enhance scalar perturbations on small scales and lead to primordial black-hole formation, including features in the inflationary potential or dynamics, noncanonical and multifield effects, modified gravity, and warm- or dissipative-inflation scenarios. Contributions addressing PBH abundance and mass functions, thermal or dissipative enhancement mechanisms, and associated scalar-induced gravitational-wave backgrounds are encouraged, particularly studies connecting inflationary model building with observational constraints across CMB, gravitational-wave, and compact-object channels. Topic editors: Xiao-Min Zhang, Li Xi-Bin, Fei Huang, Zhipeng Peng Source: https://www.frontiersin.org/research-topics/85277/emerging-paradigms-in-inflationary-cosmology