Editing Lambda-CDM model (section)

==== High-velocity galaxy problem ====
Galaxies in the [[NGC 3109]] association are moving away too rapidly to be consistent with expectations in the ΛCDM model.<ref>{{Cite journal|last1=Banik|first1=Indranil|last2=Zhao|first2=H|date=2018-01-21|title=A plane of high velocity galaxies across the Local Group|journal=Monthly Notices of the Royal Astronomical Society|volume=473|issue=3|pages=4033–4054|doi=10.1093/mnras/stx2596|arxiv=1701.06559|bibcode=2018MNRAS.473.4033B|issn=0035-8711|doi-access=free}}</ref> In this framework, [[NGC 3109]] is too massive and distant from the [[Local Group]] for it to have been flung out in a three-body interaction involving the [[Milky Way]] or [[Andromeda Galaxy]].<ref>{{Cite journal|last1=Banik|first1=Indranil|last2=Haslbauer|first2=Moritz|last3=Pawlowski|first3=Marcel S.|last4=Famaey|first4=Benoit|last5=Kroupa|first5=Pavel|date=2021-06-21|title=On the absence of backsplash analogues to NGC 3109 in the ΛCDM framework|journal=Monthly Notices of the Royal Astronomical Society|volume=503|issue=4|pages=6170–6186|doi=10.1093/mnras/stab751|arxiv=2105.04575|bibcode=2021MNRAS.503.6170B|issn=0035-8711|doi-access=free}}</ref>