BEGIN:VCALENDAR VERSION:2.0 PRODID:-//LBNL Physics Division Research Progress Meetings - ECPv6.8.3//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:LBNL Physics Division Research Progress Meetings X-ORIGINAL-URL:https://rpm.physics.lbl.gov X-WR-CALDESC:Events for LBNL Physics Division Research Progress Meetings REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:America/Los_Angeles BEGIN:DAYLIGHT TZOFFSETFROM:-0800 TZOFFSETTO:-0700 TZNAME:PDT DTSTART:20190310T100000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0700 TZOFFSETTO:-0800 TZNAME:PST DTSTART:20191103T090000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=America/Los_Angeles:20190307T160000 DTEND;TZID=America/Los_Angeles:20190307T170000 DTSTAMP:20260409T083947 CREATED:20190304T142847Z LAST-MODIFIED:20190304T142847Z UID:1037-1551974400-1551978000@rpm.physics.lbl.gov SUMMARY:Emanuele Castorina (UCB) "Cosmology with Neutral Hydrogen in the Post Eeionization Era" DESCRIPTION:ABSTRACT:\n \nMeasurements of the Cosmic Microwave Background (CMB) anisotropies and\, more recently\, of the distribution of galaxies at late times led us to the definition of a concordance cosmological model\, the so called LCDM model. Despite its phenomenological success\, several fundamental questions about the origin and fate of our Universe remain unanswered in the simplest LCDM scenario.  What mechanism\, if any\, has set up the initial conditions of the Universe? What is nature of Dark Energy? What is the value of neutrinos masses\, and are there any other light particles?\nSeveral upcoming experiments\, like DESI\, LSST and Simons Observatory\, promise to shed light on some of these misteries\, but will still be very far from the cosmic variance limit.\nIn fact most of the observable volume of the Universe lives at redshift z>2\,  where observing galaxies at high number densities becomes increasingly more difficult.\nA possible solution is offered by neutral hydrogen (HI)\, which is ubiquitous in our Universe at z<6. In emission\, HI can be mapped using the infamous 21 cm line at radio frequencies.\nIn this talk\, after summarizing the current status of 21 cm observations\, I will present the science case for a Stage-II 21 cm experiment targeting the redshift range 2