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The Early Universe As a Laboratory for Particle Physics

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The Early Universe As a Laboratory for Particle Physics The Early Universe as a Laboratory for Particle Physics Nikita Blinov April 6, 2021 York University Triumph of the Standard Model Standard Model describes properties and interactions of leptons, quarks and force carriers 100+ years of science !"#N $ift Shop 2 Triumph of the Standard Model Standard Model describes properties and interactions of leptons, quarks and force carriers 100+ years of science !"#N $ift Shop Enormous dynamic range when combined with gravity ,ar)e Hadron Collider probes ~10-20 m Cosmic Micro(ave Background: ~10+24 m 3 The Cosmological Fine Print 4n largest scales, the universe is (ell-described by a %andf l of para'eters Planck ‘18 Only 'eas red indirectly 2%y not 03 .nconsistent (it% q ant m estimates No candidate in Standard Model 4 The Expanding Universe 6ar-a(ay ob7ects (like )alaxies) are receding fro' s - bble (1929) "arlier estimates by Lemaitre (1927) and #obertson (1928) 5 The Expanding Universe 6ar-a(ay ob7ects (like )alaxies) are receding fro' s - bble (1929) 6 #iess et al 2019 Expansion in General Relativity $eneral #elativity relates expansion rate to t%e contents of the niverse Hotter and denser in the past! 7 Early Universe Primer =%e niverse e9panded from a %ot dense state "volution described by C>1 $yr 1 !o'pare (it%* Solar s rface* = ~ 0>? e@ #oo' te'p* = ~ 1AB0 e@ Galaxy formation, life etc 8 Early Universe Primer =%e niverse e9panded from a %ot dense state "volution described by C10 000 yr 1C>1 $yr !o'pare (it%* Solar s rface* = ~ 0>? e@ #oo' te'p* = ~ 1AB0 e@ -ydrogen recombination: Galaxy formation, life etc Cosmic Micro(ave Background 9 Early Universe Primer =%e niverse e9panded from a %ot dense state "volution described by t+100 sec C10 000 yr 1C>1 $yr !o'pare (it%* Solar s rface* = ~ 0>? e@ #oo' te'p* = ~ 1AB0 e@ Big Bang N cleosynthesis: ,ight nuclei made -ydrogen recombination: Galaxy formation, life etc Cosmic Micro(ave Background 10 Early Universe Primer =%e niverse e9panded from a %ot dense state "volution described by t+100 sec C10 000 yr 1C>1 $yr !o'pare (it%* Solar s rface* = ~ 0>? e@ #oo' te'p* = ~ 1AB0 e@ #eheating? DM Production? Big Bang N cleosynthesis: ,ight nuclei made -ydrogen recombination: Galaxy formation, life etc Cosmic Micro(ave Background 11 Plan For This Talk Part 1: The Hubble Tension, or what can we learn about new physics from precision cosmology Part 2: Messengers o# the pre- nucleosynthesis universe 12 Part 1: The Hubble Tension Long standing disagree'ent bet(een direct (ElocalF: 'eas re'ents of and early5ti'e inferences 0 퐻 ,ike -ubble’s ori)inal measurement Highly signi%cant tension between two of the most precise values! 13 Cosmolo)ical models track evolution of diHerent fl ids under infl ence of interactions, gravity 14 PlanckA"SA =%o'son scatterin) Quantitative Cosmology from The CMB /o(er Spectr ' S'aller angular scales larger angular scales Peaks in the Power Spectrum /eak position depends on contents of the niverse and evolution of density perturbations b/g evolution Particle densities Meas red precisely "volution of perturbations Particle Interactions See, e.)>, Pan, Kno9, M lroe & Narimani (2016) 15 The Sound Horizon is inferred fro' the an) lar scale of !MB I 0 ctuations (%ere 퐻 sound horizon Depends on evolution be#ore reco'bination 16 Distance to the CMB is inferred fro' the an) lar scale of !MB P 0 la I ctuations (%ere nc k/E 퐻 SA Depends on e9pansion after recombination 17 Hubble from the CMB is inferred fro' the an) lar scale of !MB I 0 ctuations (%ere 퐻 &nference of H0 is modified if rs is changed! 18 Origin of Phase Shift: Free-streaming Nus ● Ne trinos free5strea' and 'ake p about 41L of the energy density at early ti'es Standard assumption: neutrinos do not self-scatter ● No free5streaming if ne trinos self5interact =his changes the 19 expected phase s%iftM Origin of Phase Shift: Free-streaming Nus ● Ne trinos free5strea' and 'ake p about 41L of the energy density at early ti'es Standard assumption: neutrinos do not self-scatter ● No free5streaming if ne trinos self5interact =his changes the 20 expected phase s%iftM Solving the Hubble Tension ● Modifying amount of ne trinos c%an)es the sound %orizon ● Ne trino self-interactions can prevent free5streamin) Changing neutrino properties modi%es in#erence of H0 ! 21 Self-Interacting Neutrinos !onsistent fit to early cosmology and Riess et al 82019) H obtained in 'odels with strong ne trino self-interactions 0 Direct Meas re'ent Kreisch, Cyr5#acine & DorO (2019) .nteraction of Amount of neutrinos* neutrinos* /%ase s%ift ModiPes rs 22 Self-Interacting Neutrinos !onsistent fit to early cosmology and Riess et al 82019) H obtained in 'odels with strong ne trino self-interactions 0 Direct Meas re'ent Kreisch, Cyr5#acine & DorO (2019) .nteraction of Amount of neutrinos* neutrinos* /%ase s%ift ModiPes rs Can one have such a neutrino sel#-interaction in realistic models? 23 )*, Kelly, Krnjaic, McDermott 82019) Neutrino Self-Interactions in the SM Ne trinos self5interact in the SM, not often eno )%M /robability for a typical ne trino to 51? scatter via $6 is less than 10 during the CMB era Solution to H0 demands How do you get such a large sel#-interaction? 24 )*, Kelly, Krnjaic, McDermott (2019) Towards the “Ultra-Violet”Ultra-Violet ” Ne( light particle can mediate stron)5self interactions a'ong neutrinos 10? times lighter than Z Mediator Solve/alleviate H0 Coupling tension in these regions constant )*, Jelly, Jrnjaic, McDer'ott 82019) 25 Mediator mass Rare Meson Decays SM Prediction NA62 Experiment @ CE#N (1212.B012, 1703.08501) 26 Can also use precision pion measurements from PI"NU R =#.UM6 Searches for 0nu Double Beta Decays Neutrinoless double beta decay searches can used to search for nu self5interactions SNO+ 27 )*, Kelly, Krnjaic, McDermott (2019) Non-Free-streaming Radiation in General Experimental constraints on new physics interacting with neutrinos rule out this possibility. B t !MB only sensitive to )ravitational inI ence of ne trinos. !o ld t%ey really be something else3 28 )*, Marques5=avares (2020) Non-Free-streaming Radiation in General Experimental constraints on new physics interacting with neutrinos rule out this possibility. B t !MB only sensitive to )ravitational inI ence of ne trinos. !o ld t%ey really be something else3 neutrino-like )luon-like 29 )*, Marques5=avares (2020) Non-Free-streaming Radiation in General Experimental constraints on new physics interacting with neutrinos rule out this possibility. B t !MB only sensitive to )ravitational inI ence of ne trinos. !o ld t%ey really be something else3 neutrino-like )luon-like !he CMB can test this idea in a model-independent way 30 )*, Marques5=avares (2020) Non-Freestreaming/Interacting Radiation ● Consider extended cos'ology (ith free5strea'ing and non5free5streaming 8I id5like) radiation =3 in SM =0 in SM 6ree-streaming Non-free-streamin) (SM neutrino-like: 86luid5like) )*, Marques5=avares (2020); Brust, Cui & Si) rdson (201<:; Baumann, Green, 31 Meyers & Wallisch (2016) Constraints on Dark Radiation Allo( radiation density and free-strea'ing fraction to vary ,ocal H0 6it to cosmological data )*, Marques5=avares (2020) )o pre#erence #or beyond-+$ from early cosmology alone! +till no consistent fit to both direct H0 and '$* 32 see also Brinckmann et al (2012.11830) Photon Diffusion Damping Hu, Fukugita, Zaldarriaga & Tegmark (2000) Diff sion scale also depends on early expansion %istoryM Precise measurements at large ℓ preclude large modifications to rd relative to rs 33 Constraints on Gluon-like Radiation ● Ass 'ing the non5Abelian sector (as in thermal eq ilibriu' ntil te'perat re , can predict ab ndance at CMB 푓 푇 "9cl ded R ;?L !,U Number of “coloursF UAss 'in) no non5SM entropy in7ections 34 )*, Marques5=avares (2020: Status of the Hubble Tension Simple 'odels fail to solve the - bble tension (ithout runnin) into laboratory/cos'ology constraints 35 Status of the Hubble Tension Simple 'odels fail to solve the - bble tension (ithout runnin) into laboratory/cos'ology constraints 36 Part 2: Messengers of the Pre- Nucleosynthesis Universe distributed at really small scales The Pre-Nucleosynthesis Universe #adiation Matter Dark Energy ? NB, Dolan, Draper, Kozacz k ‘19 NB, Dolan, Draper ‘20 NB, Dolan, Draper, Shelton ‘21 &s the evolution radiation-dominated /01) all the way up( 3re there any remnants of the pre-**) universe( 38 Small Scale Distribution of Dark Matter DM distrib tion measured do(n to scales of ~ kpc /article nature of DM and its early niverse dyna'ics can leave an imprint on ' c% s'aller len)th scalesM 39 What’s stheBigDealAnyway? the Big Deal Anyway? Small scale distrib tion of DM determines potential observables; e>)> ● Direct detection e9periments searc% for energy deposition in terrestrial detectors Sensitive to DM density on scales of ~ χ χ 10 AU SuperCDMS푒 SNOLAB ● ,ig%t from distant ob7ects can be lensed by DM s bstructure 40 How Do Dark Matter Halos Form? Primordial density I ctuations )ro( ntil they be)in to self5gravitate 1) Initial conditions 2) Evolution 42 Gravitational collapse Enhanced structure can arise due to novel dynamics at any of these steps 41 Initial Conditions: Standard Assumption Density pert rbations s'all on all scales 8a'plit de of density fl ctuations)2 larger lengt% scales S'aller length scales 'an we test these assumptions? What are the alternatives( ,ength scales probed by CMB have 42 Initial Conditions: Vector Dark Matter ● DM can be “born” cl 'py @ector Dark Matter produced during inflation +105C AU51 larger lengt% scales S'aller len)th scales $ra%a', Mardon K #a7endran
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