https://www.mariangelalisanti.com/research daily 0.75 2026-03-20 https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1487563853926-E4MA873D079AGF9TQ1ND/semivisible.jpg Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1490385018351-XM5BBUJDJDJ8DRN9W8OL/2016-1-22-Gammarays.jpg Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660939774588-OKEWN45WLY24XPGIUMTQ/axions.jpg Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660944789738-DO35H6UDXXJYI9L12HLE/cluster-new2.001.png Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/03f2ff5d-7583-45d9-8c79-35944d98b421/dreams.jpg Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/b99c3d30-e41a-4560-b093-a125bac4d19b/sidm_sagittarius.png Research https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1521684399213-497JTE9GC8DRJGV7GL2F/jfactors.jpg Research - Extragalactic dark matter Dark matter particles can interact with each other, albeit very weakly. In regions of high density, such as at the centers of galaxies, dark matter particles can annihilate to produce high-energy photons that may be detectable. This image shows what the sky would like if it were lit up by such a dark matter signal---the pattern traces thousands of galaxies beyond the Milky Way. The Fermi Large Area Telescope is currently one of the most powerful probes for such dark matter signals. Using this publicly available data, we have searched for dark matter in many hundreds of galaxy groups. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1521684208978-SF1QGW4AXNRMI6MSWHBW/galacticcent.jpg Research - galactic dark matter We have also studied gamma rays produced within the Milky Way galaxy and found evidence for a new population of sources near the Galactic Center. These unresolved sources can explain, in part, an excess of high-energy photons that were previously attributed to dark matter. This analysis harnesses basic ideas from image processing to distinguish photons that are 'clumpy' rather than smoothly distributed in the sky. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/44350b3d-5e64-414a-806b-dd938aef0a80/axions.jpg Research - new experimental directions Dark matter particles are constantly streaming through the Earth, though they interact so weakly that we never notice. However, ultrasensitive detectors can be utilized to discover these faint signals. Many experiments are currently probing the parameter space relevant for Weakly Interacting Massive Particles, however new approaches are needed to broaden sensitivity to dark matter of lighter mass. We developed new experimental strategies to search for dark matter down to the keV-MeV range, and collaborated with experimentalists to use co-magnetometers to search for ultralight wave-like dark matter. Additionally, we have studied the unique features of dark matter in such direct detection experiments, including effects such as gravitational focusing and stochasticity. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1521769038612-EQC1XTBI2JIVWDHP0UBQ/semivisible.jpg Research - large hadron collider It may be possible to produce dark matter particles in the very high-energy proton collision of the Large Hadron Collider. Because the dark matter is neutral and weakly interacting, it leaves the detector with no trace and is identified as missing energy in a collision. We have worked on a variety of methods to improve searches for dark matter at colliders, including the development of Simplified Models. While initially proposed for jets plus missing energy searches, Simplified Models are now broadly used in the majority of LHC analyses. Additionally, we have developed techniques to search for a variety of challenging signals, including ‘semi-visible' jets, which arise from models with hidden dark sectors. A semi-visible jet contains quarks and gluons, as well as dark matter particles; fundamentally new search strategies are needed to discover them. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/252c294b-eed0-46c5-9b58-226c5d7349b2/cluster-new2.001.png Research - Dark Matter Cartography Building an accurate map of the spatial and velocity distribution of dark matter near the Sun requires understanding how the Milky Way galaxy evolved over time. The Milky Way grows by absorbing smaller galaxies that get caught by its strong gravitational pull. As these small galaxies orbit our own, they are eventually shredded by tidal forces, leaving behind their stars and dark matter. Evidence for such mergers lies in the stars that they leave behind, which can share distinctive clustering patterns in position, velocity, and/or chemical abundance space. We can use the reconstructed properties of these mergers to model the dark matter that was removed from them. Our ongoing work in this area is demonstrating that the local dark matter near the Sun is not in equilibrium, as typically assumed, and instead exhibits distinctive dynamics tied to the disruption of small galaxies. The updated dark matter map that we are building has important ramifications for direct detection experiments, which search for the interactions of these particles in terrestrial targets. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/c8d569ac-272a-46b4-839a-cb5b966e57d4/dreams.jpg Research - Galaxy Simulations Visible galaxies form at the centers of vast dark matter halos, and their properties are sensitive to features of these halos. For example, the density distribution of a halo, including its smaller-scale substructure, can leave observable footprints through its gravitational impact on the visible matter. Our group studies how variations in the dark matter model can affect galaxy formation and evolution and develops the numerical simulations needed to accurately model these effects for current and upcoming astrophysical observatories, including the Rubin Observatory, Nancy Grace Roman Telescope, JWST, and Euclid. Our recent work focuses on Cold Dark Matter, as well as models where the dark matter can interact with itself, either elastically or inelastically. For some images and movies based on our simulations, see: Cold and Warm Dark Matter: The DREAMS Project Elastic Self-Interacting Dark Matter: Hainje et al. Inelastic Self-Interacting Dark Matter: Roy et al. and Mandacarú Guerra et al. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/f066efbe-cce7-4a80-9a19-c0cc0d9b4ae6/sidm_sagittarius.png Research - Small-Scale structure The Cold Dark Matter (CDM) paradigm has been remarkably successful at predicting large-scale properties of the Universe, from the Cosmic Microwave Background to the web of galaxies. The next frontier is to test it on galactic and sub-galactic scales. The CDM model predicts that the dark matter is cold and collisionless, however well-motivated theoretical scenarios suggest that it may be far more complex: the dark matter can consist of multiple particles that interact with themselves and regular matter through new forces. Such interesting dynamics will typically manifest on the smallest galaxy scales. Our group has been extensively studying the properties of Milky Way satellite galaxies, field dwarf galaxies, and stellar streams to better understand their sensitivity to the specifics of the dark matter model. Our work is guided by the exciting observational program underway that is opening a window to halos at unprecedentedly small mass and early epochs. https://www.mariangelalisanti.com/outreach-database daily 0.75 2026-03-30 https://www.mariangelalisanti.com/outreach-database/2026/3/18/underland monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/outreach-database/2026/3/18/what-an-austrian-cow-fermilab-teach-us-about-science-discovery monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/outreach-database/2026/3/18/science-is-inherently-uncertain-thats-a-good-thing monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/outreach-database/2026/3/18/rock-stars-of-american-science-may-take-their-expertise-abroad monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/outreach-database/2026/3/18/dark-matter-waves-from-the-cosmos-to-the-lab monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/outreach-database/2026/3/18/dark-matter-archeology monthly 0.5 2026-03-20 https://www.mariangelalisanti.com/join daily 0.75 2022-08-19 https://www.mariangelalisanti.com/publications daily 0.75 2026-03-18 https://www.mariangelalisanti.com/homepage daily 1.0 2022-08-19 https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660935300650-5P88JPZJW6RXS22SLBRE/galaxy.jpeg Home The fact that galaxies rotate faster than expected is a strong indicator that we only see a small fraction of all the matter that exists—the additional mass comes from “dark matter.’’ [Credit: NASA/JPL-Caltech] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1487646981537-QI8WAJWPD29JRVZ2T2U0/jarrett_Fig1+%281%29.jpg Home The large-scale structure of galaxies across the Universe teaches us about the properties of dark matter. [Image: 2MASS Redshift Survey] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660932089535-AKTZP8RYBPU6BQU524O3/gaia.jpg Home The properties of dark matter can affect the dynamics of galaxies like our own, which can be tested with astrophysical observatories such as Gaia. [Image: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660934041884-LHR33ZQWO0SDNXW16YFT/streams.jpeg Home Dark matter can affect the observable properties of small dwarf galaxies that are colliding with the Milky Way. [Credit: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1487647058564-5YGM3ULWTEPC3WTB1932/Fermi_5_year.jpg Home Signals of dark matter from annihilations at the centers of galaxies may be hiding in high-energy gamma-rays. [Image: Fermi All-Sky Map] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1487646487310-LONP15DBIT7HRBAVV9SK/L800kpc_z0_0.jpeg Home Simulations of dark matter help us understand its astrophysical distribution in the Milky Way and beyond. [Image: Via Lactea Simulation] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660945397683-FQO57LKG203ES81T4X0E/gammagamma.png Home Dark matter may be produced at the Large Hadron Collider and other accelerator experiments. [Image: CERN] https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/1660931699415-JLMFODIVM1662LASX177/snolab.jpg Home Dark matter signals in experiments can be so weak that they require incredibly sensitive detectors. https://www.mariangelalisanti.com/review-articles daily 0.75 2022-10-01 https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/9059ff3f-4a33-4f67-8c08-939db0941f42/image-asset.jpg Review Articles - Lectures on dark matter physics TASI Lectures on Dark Matter Physics https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/49501949-5674-42eb-9877-936b3817cc1b/Snowmass.jpg Review Articles - snowmass 2021 white paper https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/f742eab3-2807-419a-80da-fa75cf3032dc/image-asset.jpg Review Articles - Dark Sectors/Cosmic Visions Carlos Howard The following is placeholder text known as “lorem ipsum,” which is scrambled Latin used by designers to mimic real copy. Nulla eu pretium massa. Donec ac fringilla turpis. In sit amet felis malesuada, feugiat purus eget, varius mi. https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/9b2d71b5-8df8-422c-a2b5-2bd30baefee4/image-asset.jpg Review Articles - Annual modulation review https://images.squarespace-cdn.com/content/v1/58a8b368d1758e8411790a59/f59547d3-33f0-4405-86d4-c4e4083ea34c/Untitled.jpg Review Articles - Simplified models review Daniel Aiko The following is placeholder text known as “lorem ipsum,” which is scrambled Latin used by designers to mimic real copy. Vivamus a ante congue, porta nunc nec, hendrerit turpis. Suspendisse nec congue purus. Donec eu est non lacus lacinia semper. Phasellus sodales massa malesuada tellus fringilla, nec bibendum tellus blandit. 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