NeutrinoCenter.org | Neutrino Cosmology

Neutrino Cosmology Topics

Neutrino cosmology studies how neutrinos influence the origin, evolution, composition, and large-scale structure of the Universe, and how cosmological observations constrain neutrino properties.

1. Foundations of Neutrino Cosmology

1. Role of neutrinos in the early Universe

2. Cosmological expansion and neutrino evolution

3. Neutrinos in the Standard Cosmological Model

4. Neutrinos in the ΛCDM model

5. Relativistic and nonrelativistic neutrino populations

6. Thermal history of cosmic neutrinos

7. Neutrino phase-space distributions

8. Neutrino thermodynamics

9. Neutrino entropy density

10. Neutrino contribution to cosmic energy density

2. Cosmic Neutrino Background

11. Cosmic Neutrino Background, or CνB

12. Formation of the relic neutrino background

13. Neutrino decoupling in the early Universe

14. Neutrino decoupling temperature

15. Present-day relic neutrino temperature

16. Relic neutrino number density

17. Fermi–Dirac distribution of relic neutrinos

18. Non-instantaneous neutrino decoupling

19. Spectral distortions in the cosmic neutrino background

20. Gravitational clustering of relic neutrinos

21. Local relic-neutrino overdensity

22. Direct detection of the cosmic neutrino background

23. Neutrino capture on beta-decaying nuclei

24. PTOLEMY-type relic-neutrino experiments

25. Dirac-versus-Majorana signatures in relic-neutrino detection

3. Neutrinos in the Early Universe

26. Thermal production of neutrinos

27. Weak-interaction rates in the primordial plasma

28. Neutrino-electron interactions

29. Neutrino–antineutrino annihilation

30. Neutrino freeze-out

31. Neutrino reheating during electron–positron annihilation

32. Evolution of neutrino temperature

33. Quantum kinetic evolution of early-Universe neutrinos

34. Neutrino density matrices

35. Flavor coherence in the early Universe

36. Neutrino collision terms

37. Neutrino transport equations

38. Boltzmann equations for cosmological neutrinos

39. Neutrino quantum kinetic equations

40. Finite-temperature corrections to neutrino interactions

4. Effective Number of Relativistic Species

41. Effective number of neutrino species, (N_{\mathrm{eff}})

42. Standard-Model prediction for (N_{\mathrm{eff}})

43. Cosmological measurement of (N_{\mathrm{eff}})

44. Extra relativistic degrees of freedom

45. Dark-radiation contributions

46. Sterile-neutrino contributions to (N_{\mathrm{eff}})

47. Partial thermalization of new particles

48. Nonstandard reheating and (N_{\mathrm{eff}})

49. Constraints on light hidden-sector particles

50. Degeneracy between (N_{\mathrm{eff}}) and cosmological parameters

5. Big Bang Nucleosynthesis and Neutrinos

51. Neutrino effects on Big Bang nucleosynthesis

52. Neutron-to-proton conversion rates

53. Weak freeze-out and primordial element production

54. Primordial helium abundance

55. Primordial deuterium abundance

56. Lithium abundance and the cosmological lithium problem

57. Effects of (N_{\mathrm{eff}}) on nucleosynthesis

58. Effects of neutrino chemical potentials

59. Electron-neutrino spectral distortions

60. Sterile neutrinos during nucleosynthesis

61. Nonstandard neutrino interactions and BBN

62. Decaying particles and neutrino injection during BBN

63. Joint BBN and cosmic microwave background constraints

6. Neutrino Mass in Cosmology

64. Cosmological limits on neutrino masses

65. Sum of neutrino masses, (\sum m_\nu)

66. Minimum neutrino mass from oscillation experiments

67. Normal neutrino mass ordering in cosmology

68. Inverted neutrino mass ordering in cosmology

69. Quasi-degenerate neutrino masses

70. Relativistic-to-nonrelativistic transition of neutrinos

71. Neutrino mass fraction of matter

72. Neutrino mass density parameter, (\Omega_\nu)

73. Neutrino mass and the expansion history

74. Neutrino mass and cosmic age

75. Model dependence of cosmological mass constraints

76. Combining cosmology with beta-decay experiments

77. Combining cosmology with neutrinoless double-beta decay

78. Prospects for determining neutrino mass ordering cosmologically

7. Neutrino Free Streaming

79. Neutrino free-streaming mechanism

80. Neutrino free-streaming length

81. Neutrino free-streaming scale

82. Suppression of matter perturbations

83. Scale-dependent growth of structure

84. Neutrino Jeans scale

85. Neutrino thermal velocities

86. Transition from radiation-like to matter-like behavior

87. Neutrino anisotropic stress

88. Free-streaming signatures in cosmological observables

89. Non-free-streaming neutrino models

90. Strongly interacting neutrino cosmologies

8. Large-Scale Structure and Neutrinos

91. Neutrino effects on the matter power spectrum

92. Linear structure formation with massive neutrinos

93. Nonlinear structure formation with neutrinos

94. Neutrino effects on galaxy clustering

95. Scale-dependent matter growth rate

96. Redshift-space distortions and neutrino mass

97. Baryon acoustic oscillations and neutrinos

98. Neutrino effects on cosmic voids

99. Neutrino effects on galaxy clusters

100. Cluster abundance constraints on neutrino mass

101. Halo mass function with massive neutrinos

102. Halo bias in massive-neutrino cosmologies

103. Neutrino clustering around dark-matter halos

104. Neutrino wakes behind moving halos

105. Scale-dependent galaxy bias

106. Lyman-alpha forest constraints on neutrinos

107. 21-centimeter cosmology and neutrino mass

108. Peculiar-velocity surveys and neutrinos

9. Cosmic Microwave Background and Neutrinos

109. Neutrino effects on CMB temperature anisotropies

110. Neutrino effects on CMB polarization

111. CMB acoustic peak shifts

112. CMB phase-shift signatures of free-streaming particles

113. Early integrated Sachs–Wolfe effect

114. Neutrino anisotropic stress in the CMB

115. CMB lensing and neutrino mass

116. CMB damping tail and (N_{\mathrm{eff}})

117. Matter–radiation equality and neutrinos

118. CMB constraints on the neutrino mass sum

119. CMB constraints on neutrino interactions

120. CMB spectral distortions from neutrino physics

121. CMB–large-scale-structure joint analyses

122. CMB Stage-4 sensitivity to neutrino properties

10. Cosmological Neutrino Perturbations

123. Neutrino density perturbations

124. Neutrino velocity perturbations

125. Neutrino pressure perturbations

126. Neutrino anisotropic-stress perturbations

127. Adiabatic neutrino perturbations

128. Neutrino isocurvature perturbations

129. Neutrino velocity-isocurvature modes

130. Boltzmann hierarchy for neutrino perturbations

131. Fluid approximations for massive neutrinos

132. Gauge dependence of neutrino perturbations

133. Initial conditions for cosmological neutrino modes

134. Linear-response treatment of neutrino clustering

11. Neutrino Flavor Evolution in Cosmology

135. Early-Universe neutrino oscillations

136. Three-flavor oscillations in the primordial plasma

137. Matter effects on cosmological neutrinos

138. Neutrino self-interaction potentials

139. Collective neutrino oscillations

140. Flavor equilibration before nucleosynthesis

141. Mikheyev–Smirnov–Wolfenstein effects in the early Universe

142. Lepton-asymmetry-driven flavor conversion

143. Active–sterile neutrino oscillations

144. Resonant sterile-neutrino production

145. Quantum decoherence of cosmological neutrinos

146. CP-violating effects in early-Universe oscillations

12. Cosmological Lepton Asymmetry

147. Lepton asymmetry of the Universe

148. Neutrino chemical potentials

149. Neutrino degeneracy parameters

150. Flavor-dependent lepton asymmetries

151. Constraints on lepton asymmetry from BBN

152. Constraints from the cosmic microwave background

153. Lepton-asymmetry generation mechanisms

154. Affleck–Dine leptogenesis

155. Neutrino oscillations and asymmetry redistribution

156. Large lepton asymmetry with small baryon asymmetry

157. Lepton-isocurvature perturbations

13. Neutrinos and Baryogenesis

158. Neutrino connection to the matter–antimatter asymmetry

159. Leptogenesis

160. Thermal leptogenesis

161. Resonant leptogenesis

162. Flavored leptogenesis

163. Low-scale leptogenesis

164. Leptogenesis through neutrino oscillations

165. Heavy Majorana neutrinos in the early Universe

166. Right-handed neutrino production

167. Seesaw mechanisms and cosmology

168. CP violation in the neutrino sector

169. Sphaleron conversion of lepton asymmetry

170. Cosmological tests of leptogenesis models

14. Sterile Neutrino Cosmology

171. Sterile neutrinos in the early Universe

172. Thermalization of sterile neutrinos

173. Sterile-neutrino dark radiation

174. Sterile-neutrino mass constraints

175. eV-scale sterile neutrinos

176. keV-scale sterile neutrinos

177. Heavy sterile neutrinos

178. Sterile-neutrino production mechanisms

179. Dodelson–Widrow production

180. Shi–Fuller resonant production

181. Sterile-neutrino decay

182. Sterile-neutrino effects on structure formation

183. Sterile-neutrino warm dark matter

184. X-ray constraints on sterile-neutrino decay

185. BBN and CMB limits on sterile neutrinos

186. Secret interactions of sterile neutrinos

15. Neutrinos and Dark Matter

187. Neutrinos as hot dark matter

188. Relic neutrino contribution to dark matter

189. Sterile neutrinos as warm dark matter

190. Neutrino–dark-matter interactions

191. Neutrino portals to the dark sector

192. Dark-matter annihilation into neutrinos

193. Dark-matter decay into neutrinos

194. Neutrinophilic dark matter

195. Neutrino signals from cosmological dark-matter decay

196. Dark-matter effects on cosmic neutrino propagation

197. Dark-sector thermalization through neutrinos

198. Mixed cold-plus-hot dark-matter models

199. Structure-formation limits on neutrino dark matter

200. Phase-space constraints on fermionic dark matter

16. Nonstandard Neutrino Interactions

201. Cosmological nonstandard neutrino interactions

202. Neutrino self-interactions

203. Neutrino–electron nonstandard interactions

204. Neutrino–quark interactions in the early Universe

205. Neutrino–dark-radiation interactions

206. Neutrino–majoron interactions

207. Neutrino interactions mediated by light bosons

208. Secret neutrino interactions

209. Delayed neutrino free streaming

210. Neutrino recoupling

211. Neutrino opacity in the early Universe

212. CMB signatures of interacting neutrinos

213. BBN limits on nonstandard interactions

214. Large-scale-structure constraints on interacting neutrinos

17. Neutrino Decay and Cosmology

215. Cosmological neutrino decay

216. Visible neutrino decay

217. Invisible neutrino decay

218. Radiative neutrino decay

219. Majoron-mediated neutrino decay

220. Neutrino lifetime constraints from cosmology

221. Decay of nonrelativistic relic neutrinos

222. Effects of neutrino decay on the CMB

223. Effects of neutrino decay on matter clustering

224. Neutrino decay into dark radiation

225. Unstable sterile neutrinos

226. Cosmological signatures of neutrino regeneration

18. Neutrino Electromagnetic Properties

227. Cosmological constraints on neutrino magnetic moments

228. Neutrino electric dipole moments

229. Neutrino millicharge

230. Neutrino charge radius

231. Spin-flavor conversion in primordial magnetic fields

232. Right-handed-neutrino production through magnetic moments

233. Neutrino–photon interactions

234. Radiative neutrino processes in the early Universe

235. Primordial magnetic fields and neutrino transport

236. BBN and CMB limits on electromagnetic neutrino properties

19. Neutrinos and Inflation

237. Neutrino production during inflation

238. Right-handed neutrinos during inflation

239. Neutrino isocurvature perturbations

240. Inflationary origin of lepton asymmetry

241. Neutrino coupling to the inflaton

242. Reheating through neutrino interactions

243. Neutrino-assisted reheating

244. Seesaw inflation models

245. Sterile-neutrino production during reheating

246. Nonthermal neutrino distributions after inflation

247. Primordial non-Gaussianity from neutrino sectors

248. Heavy-particle signatures in primordial correlations

20. Neutrinos and Dark Energy

249. Neutrino mass–dark-energy degeneracy

250. Mass-varying neutrinos

251. Neutrino coupling to scalar dark energy

252. Neutrino-triggered cosmic acceleration

253. Neutrino lumps in coupled dark-energy models

254. Dynamical dark energy and neutrino mass constraints

255. Early dark energy and (N_{\mathrm{eff}})

256. Modified expansion histories and neutrino bounds

257. Neutrino–quintessence interactions

258. Cosmological stability of mass-varying-neutrino models

21. Neutrinos and Modified Gravity

259. Neutrino mass constraints in modified-gravity cosmologies

260. Degeneracy between massive neutrinos and modified gravity

261. Scalar–tensor gravity and neutrinos

262. (f(R)) gravity with massive neutrinos

263. Neutrino clustering in alternative-gravity theories

264. Scale-dependent growth from gravity and neutrino mass

265. Weak-lensing tests of gravity–neutrino degeneracies

266. Effective-field-theory descriptions

267. Modified gravity, CMB lensing, and neutrinos

22. High-Energy Neutrinos in Cosmology

268. Cosmological propagation of high-energy neutrinos

269. Redshift effects on neutrino energy spectra

270. Diffuse cosmogenic neutrino background

271. Neutrinos from ultrahigh-energy cosmic rays

272. Greisen–Zatsepin–Kuzmin neutrinos

273. Neutrino interactions with the cosmic neutrino background

274. Resonant neutrino annihilation on relic neutrinos

275. Z-burst mechanism

276. Absorption features in cosmic-neutrino spectra

277. Neutrino cascades over cosmological distances

278. Constraints on cosmic evolution of neutrino sources

279. Neutrinos from early-Universe phase transitions

280. Neutrinos from cosmic strings and topological defects

23. Neutrinos from Cosmological Transients

281. Neutrinos from gamma-ray bursts

282. Neutrinos from Population III stars

283. Neutrinos from primordial supernovae

284. Neutrinos from supermassive black-hole formation

285. Neutrinos from binary neutron-star mergers

286. Neutrinos from black-hole–neutron-star mergers

287. Neutrinos from tidal disruption events

288. Diffuse supernova neutrino background

289. Redshift evolution of the supernova neutrino background

290. Cosmic star-formation history from neutrinos

291. Neutrino backgrounds from active galactic nuclei

292. Multimessenger cosmology with neutrinos

24. Primordial Black Holes and Neutrinos

293. Neutrino emission from primordial black-hole evaporation

294. Hawking radiation of neutrinos

295. Neutrino constraints on primordial black holes

296. Primordial black holes as sources of sterile neutrinos

297. Neutrino backgrounds from evaporating black holes

298. Effects of primordial black holes on BBN

299. Black-hole reheating and neutrino production

300. Primordial black-hole domination before nucleosynthesis

25. Exotic Cosmological Neutrino Physics

301. Neutrino Lorentz-invariance violation

302. Neutrino CPT violation

303. Quantum-gravity effects on cosmic neutrinos

304. Neutrino decoherence over cosmological distances

305. Variation of neutrino parameters with cosmic time

306. Neutrino equivalence-principle tests

307. Extra dimensions and cosmological neutrinos

308. Neutrinos in braneworld cosmology

309. Neutrino interactions with axions and axion-like particles

310. Majorons in cosmology

311. Neutrino condensates

312. Neutrino superfluidity

313. Tachyonic-neutrino cosmology

314. Mirror-neutrino cosmology

315. Neutrinos in cyclic and bouncing cosmologies

26. Cosmological Observations and Surveys

316. Planck constraints on neutrino properties

317. ACT and SPT neutrino constraints

318. CMB-S4 forecasts

319. Simons Observatory forecasts

320. DESI constraints on neutrino mass

321. Euclid neutrino cosmology

322. Vera C. Rubin Observatory neutrino constraints

323. Nancy Grace Roman Space Telescope surveys

324. Square Kilometre Array neutrino cosmology

325. Hydrogen Epoch of Reionization Array constraints

326. 21-centimeter intensity-mapping surveys

327. Weak gravitational-lensing surveys

328. Galaxy-cluster surveys

329. Lyman-alpha forest measurements

330. Cross-correlation of cosmological datasets

27. Computational Neutrino Cosmology

331. Cosmological Boltzmann codes

332. Neutrinos in CLASS

333. Neutrinos in CAMB

334. Big Bang nucleosynthesis codes

335. Quantum kinetic simulation codes

336. Massive-neutrino N-body simulations

337. Particle-based neutrino simulations

338. Grid-based neutrino simulations

339. Linear-response neutrino methods

340. Hybrid neutrino simulation techniques

341. Neutrino transfer functions

342. Nonlinear matter-power-spectrum modeling

343. Neutrino emulators

344. Hydrodynamical simulations with massive neutrinos

345. Machine learning for neutrino cosmology

346. Bayesian parameter inference

347. Markov-chain Monte Carlo analysis

348. Fisher-matrix forecasts

349. Cosmological likelihood construction

350. Systematic uncertainties in neutrino parameter estimation

28. Major Research Questions

351. What is the absolute neutrino mass scale?

352. What is the cosmological sum of neutrino masses?

353. Can cosmology determine the neutrino mass ordering?

354. Can the cosmic neutrino background be detected directly?

355. Are there additional relativistic particle species?

356. Did sterile neutrinos exist in the early Universe?

357. Are cosmic neutrinos free-streaming or interacting?

358. Is there a significant cosmological lepton asymmetry?

359. Did neutrino physics generate the baryon asymmetry?

360. Are neutrinos connected to dark matter?

361. Are neutrinos connected to dark energy?

362. Do neutrino masses vary over cosmic time?

363. Are neutrinos stable on cosmological timescales?

364. Are neutrinos Dirac or Majorana particles?

365. Can neutrinos reveal physics beyond ΛCDM?

366. Can high-energy neutrinos probe the cosmic neutrino background?

367. Can future surveys reach the minimum neutrino mass predicted by oscillations?

368. Could neutrino cosmology reveal new fundamental interactions?

A useful top-level hierarchy for PhysicsIndex.org would be:

Neutrino Cosmology → Early-Universe Neutrinos → Cosmic Neutrino Background → BBN → CMB → Neutrino Mass → Large-Scale Structure → Leptogenesis → Sterile Neutrinos → Dark-Sector Connections → High-Energy Cosmological Neutrinos → Observations and Simulations.