Cosmological and astrophysical observations currently provide the only robust, positive empirical evidence for the existence of dark matter. Furthermore, cosmic probes of dark matter, which seek to determine the fundamental properties of dark matter through observations of the cosmos, have emerged as a promising means to reveal the nature of dark matter. Cosmic survey projects provide a unique...
DESI is pushing the boundaries in terms of the depth and number of spectroscopic redshifts being collected. The ambitious DESI-II and Spec5 programs will collect even larger samples of deep spectra for intermediate-mass galaxies at $z<1$. These samples will greatly serve to improve our understanding of the connection between galaxies and dark matter at $z<1$. I will discuss how this...
Workforce development remains a high priority for the DoE High Energy Physics program. Scientists and engineers who currently participate in DoE projects were often introduced to research as undergraduates at our Universities. Preserving a strong and continuous human and facilities infrastructure at our nation's universities is essential to maintaining an effective and sustainable program...
Observational Cosmology is driven by large collaborative experiments like Rubin, JWST, or Euclid. Discovery in these surveys necessitates the development of advanced analysis methodology, high-precision instrumentation, and collaborative work in large interdisciplinary collaborations. Synergies between different survey programs will be crucial to reach the science goals of upcoming survey...
Renewable energy sources are widely recognized for their ability to provide affordable, reliable energy with reduced environmental impact. As existing and future High-Energy Physics (HEP) experiments probe the Snowmass science drivers over the coming decades, renewable energy must be considered for integration into the supporting infrastructure. Each experimental site will offer challenges...
For the past 15 years at least, French labs (CEA-Saclay, INSU/IPA, INSU/LAM, IN2P3/LPNHE and IN2P3/CPPM) have successfully collaborated with DOE labs on wide-field spectroscopic surveys (BOSS, eBOSS, DESI). These contributions cover all the range from construction of the instrument to survey design and later data analysis. In BOSS/eBOSS, the French teams provided their expertise on the...
Funding for microelectronics presents a tremendous opportunity for developing the next generation of tools enabling the cosmic frontier. The funding has focused on the very valuable ASIC (Application Specific Integrated Circuit) design and fabrication. Taking full advantage of these developments requires dedicated support for their implementation in HEP experiments, in the intersection...
The dark matter parameter space is enormous and there is no one-size-fits-all experiment that can cover it all. Dozens of proposals for novel experiments exist in the literature but are stymied from "graduating" from the page to the laboratory by a lack of funding opportunities for small-scale experiments at the 100k level. The recent Dark Matter New Initiatives program from DOE provides an...
A unique aspect of the next-generation astronomical surveys as a probe of dark energy and dark matter is in the use of multiple cross-checking probes observed with unprecedented precision. Due to the dataset complexity and size, working with the next-generation astronomical datasets will be challenging, and many tasks will either be too slow or not possible at all with classical approaches....
Dear P5 members,
The last decade has seen tremendous progress in Cosmic Frontier research, including significant advances in measuring the properties of Dark Energy, several orders of magnitude increase in sensitivity to Dark Matter over a variety of different mass scales, compelling arguments for the existence of new physics beyond the Standard Model, and a strong record of delivery on...
Weak lensing science will enter into its prime as a cosmological probe over the coming decade, but we will not be able to fully exploit weak lensing measurements without supplemental cross-correlation measurements between weak lensing, spectroscopic galaxy surveys and the CMB. I will discuss ways that overlap between upcoming surveys such as Rubin, CMB S4 and Stage V spectroscopy can serve to...
The world-leading sensitivity of dark matter experiments such as LUX-ZEPLIN (LZ) is enabled by a strong foundation of liquid xenon detector research. However, many aspects of xenon detector technology are relatively unexplored, and potential improvements through R&D can dramatically extend the sensitivity of current experiments.
Examples of active areas of research to improve existing...
Spectroscopic observations with wide field, extremely sensitive facilities like DESI-II and S5 can constrain the particle properties of dark matter through observations of the smallest cosmic structures in the Milky Way and local universe. The mass, interaction cross-section and other properties of dark matter help set the important physical scales in these systems. The mass spectrum and...
Observations of the cosmic microwave background (CMB) have been pivotal in establishing $\Lambda$CDM as the standard model of cosmology and are providing a critical avenue for the exploration of particle physics beyond the standard model. CMB-S4 is the pivotal next step in CMB observations and, especially when combined with large scale optical surveys such as DESI and LSST, will significantly...
The Dark Energy Spectroscopic Instrument provided many opportunities for early career scientists to involve themselves with the construction and commissioning on the instrument. Much of my training as a scientist has been through working on DESI construction, commissioning and early analysis of data. Following the development of a project in one's early career is a unique and formative...
The large-scale structure in the Universe is a marvelous laboratory for the study of cosmological physics. By measuring the detailed statistics of the clustering, we can explore important extensions of the standard cosmological model: variations in dark energy density, modifications to large-scale gravity, non-vanilla primordial initial conditions (changes in the primordial power spectrum,...
Line intensity mapping at millimeter wavelengths is a promising method of measuring large-scale structure and constraining cosmology, potentially beyond the reach of future optical surveys. I will outline the path forward to deploying future instruments with the required sensitivity for next-generation cosmological constraints, including developing large-format on-chip spectrometers and...
Upcoming imaging and spectroscopic surveys will provide unprecedented constraints on models of dark energy and cosmic inflation. I will briefly discuss key synergies between these two types of surveys that will enable us to maximize science returns in the coming decades, including the use of spectroscopy to directly calibrate and optimize weak lensing surveys such as LSST. Facilitating...
Recommended by the last P5 committee, construction of the Dark Energy Spectroscopic Instrument (DESI) began in 2014. Led by Lawrence Berkeley National Lab, major components of the new instrument were developed and built by university groups both in the US and in Europe.
The spectrograph mechanisms, the commissioning instrument and the instrument control and monitoring system were developed...
CMB experiments have contributed powerful constraints on the fundamental physics of the Universe. Upcoming CMB experiments such as the Simons Observatory and CMB-S4 are poised to extend this progress even further. However, CMB experiments still have a wealth of information to offer beyond these near-term facilities regarding the properties of dark matter, inflation, light relic particles,...
As discussed at Snowmass, there is great interest in a lepton collider in the energy range of 10 TeV and beyond, where colliding elementary particles are anticipated to offer powerful signatures for discovery science. Ultrahigh-gradient Advanced Accelerator Concepts (AAC) offer an attractive path to enable such future colliders by significantly shrinking their size and enhancing their energy...
Simulations have been and continue to play a crucial role in cosmic frontier surveys. As we explore further into uncharted science with increasingly precise measurements, the need for accurate theoretical predictions and cross-correlation measurements will only rise. The simulation challenges of the next decade involve not only enhancing physics modeling fidelity, but also the ability to fully...
The future of cosmology looks bright: several ground and space telescopes being built, thousands of people coming together in an effort to uncover the riddles of dark matter and dark energy. No one can deny the wealth of data that these detectors will bring. However, it would be beneficial to examine if our strategies and analysis choices will help answer fundamental questions. In this rush to...
Our ability to learn more about the properties of dark energy and dark matter involve combining information from a range of different cosmology probes. It is vital that we develop accurate models of the systematic errors that affect these measurements, so that we measure unbiased values of the cosmological parameters. We will also need to obtain spectroscopic redshifts for large numbers of...
