The energy shear of protohaloes
As it collapses to form a halo, the shape of a protohalo patch is deformed by the initial shear field. This deformation is often modeled using the ‘deformation’ tensor, constructed from second derivatives of the gravitational potential, whose trace gives the initial overdensity. However, especially for lower mass protohaloes, this matrix is not always positive definite: one of its eigenvalues has a different sign from the others. We argue that the evolution of a patch is better described by the ‘energy shear’ tensor, which is actually positive definite and plays a direct role in the evolution, and test our analytical result against N-body simulations. We discuss the implications of this positive-definiteness for analytical models of halo abundances, assembly and of the cosmic web.
Authors
- Ravi K. Sheth (ORCID: https://orcid.org/0000-0002-2330-0917)
- Giulia Despali (ORCID: https://orcid.org/0000-0001-6150-4112)
- Marcello Musso (ORCID: https://orcid.org/0000-0003-1640-2795)
Institutions
- The Abdus Salam International Centre for Theoretical Physics (ICTP) (IT)
- Universidad de Salamanca (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (IT)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Pennsylvania (US)
- University of Bologna (IT)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2024-09-05
- DOI
- https://doi.org/10.1051/0004-6361/202450985
- Citations
- 3
- Primary Topic
- Quantum, superfluid, helium dynamics
- Type
- article
- Field-Weighted Citation Impact
- 1.01
Funders
- National Science Foundation
- Ministerio de Ciencia, Innovación y Universidades
- European Commission
- Abdus Salam International Centre for Theoretical Physics
- Ministerio de Ciencia e Innovación
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara