Astroparticle Physics and Particle Cosmology

Astroparticle physics and particle cosmology unite the study of fundamental interactions with observations of the Universe. By tracing high-energy particles and quantum fields across cosmic history, this field addresses how elementary particles shape structure from the Big Bang to the present day. Key messengers include photons (from radio to gamma rays), cosmic-ray nuclei and leptons, neutrinos, and gravitational waves, each probing acceleration sites—from supernova remnants to active galactic nuclei—and the properties of dark matter, dark energy and inflation. The cosmic microwave background (CMB) preserves the imprint of primordial sound waves, while baryon acoustic oscillations (BAO) in galaxy surveys map the same physics at later epochs. Weak gravitational lensing (cosmic shear) reveals the growth of large-scale structure and tests gravity. These cosmological observables complement collider and direct-detection experiments, constraining Beyond-Standard-Model scenarios—such as light relic particles, sterile neutrinos, axion‐like fields and Weakly Interacting Massive Particles—with subpercent precision on parameters like the radiation density, the dark‐matter annihilation rate and neutrino masses. Interconnections between laboratory measurements, satellite missions and ground-based telescopes characterise the fundamental particle content of the Universe and its dynamical evolution.

Research from Nature Portfolio

Joint analysis of galaxy power spectra measured before and after density-field reconstruction has been shown to recover higher-order cosmological information in a two-point statistic alone. By combining pre- and post-reconstruction data, this method increases the information yield on distance and growth-rate parameters without explicit higher-order correlators, paving the way for enhanced BAO and redshift-space distortion studies in upcoming wide-field surveys.

A novel detection of the BAO feature in the cross-correlation between galaxy positions and galaxy ellipticities has validated lensing-induced shape correlations as an independent standard ruler. Using spectroscopic samples and high-precision shape catalogues, the measurement achieves few-percent precision on comoving distances and demonstrates a ~10 % reduction in uncertainty when combined with traditional galaxy clustering, highlighting a new pathway to systematics control in future CMB and large-scale-structure experiments.

Astroparticle Physics and Particle Cosmology publication trend

The graph below shows the total number of articles in astroparticle physics and particle cosmology across all publications each year (not limited to Nature Index journals).

Technical terms

Baryon acoustic oscillations (BAOs): Periodic modulations in the matter distribution originating from sound waves in the early photon–baryon plasma, providing a standard ruler for cosmic distances.

Density-field reconstruction: A technique that estimates and reverses large-scale displacements induced by non-linear evolution, sharpening the BAO signal in galaxy surveys.

Galaxy–ellipticity cross-correlation: The statistical correlation between galaxy positions and shapes, sensitive to lensing-induced distortions and capable of revealing BAO features via cosmic shear.

Decaying dark matter: Dark-matter models in which a parent particle decays into lighter products, injecting energy and suppressing small-scale structure depending on the decay lifetime and mass splitting.

Scotogenic WIMP: A heavy, radiatively generated dark-matter candidate whose annihilation into Standard-Model particles yields multiwavelength emission with a distinctive triple-peak spectrum.

Stochastic gravitational-wave background (SGWB): A diffuse superposition of unresolved gravitational waves from many sources—such as cosmic-string loop oscillations—characterised by a continuous spectrum across frequencies.

References

1. Extracting high-order cosmological information in galaxy surveys with power spectra. Communications Physics (2024).
2. Evidence for baryon acoustic oscillations from galaxy–ellipticity correlations. Nature Astronomy (2023).
3. Probing the two-body decaying dark matter scenario with weak lensing and the cosmic microwave background. Astronomy & Astrophysics (2024).
4. MHz to TeV expectations from scotogenic WIMP dark matter. Monthly Notices of the Royal Astronomical Society (2024).
5. Primordial black hole archaeology with gravitational waves from cosmic strings. Journal of High Energy Physics (2023).