pith. the verified trust layer for science. sign in

arxiv: 2605.13965 · v1 · pith:YELD3LLOnew · submitted 2026-05-13 · 🌀 gr-qc · hep-th

Multipolar Proca stars: electric, magnetic and hybrid solitons

Pith reviewed 2026-05-15 02:35 UTC · model grok-4.3

classification 🌀 gr-qc hep-th
keywords procastarsconfigurationselectrichybridmagneticangularcases
0
0 comments X p. Extension
Add this Pith Number to your LaTeX paper What is a Pith Number?
\usepackage{pith}
\pithnumber{YELD3LLO}

Prints a linked pith:YELD3LLO badge after your title and writes the identifier into PDF metadata. Compiles on arXiv with no extra files. Learn more

The pith

New multipolar electric, magnetic, and hybrid Proca stars are constructed as self-gravitating solutions in Einstein-Proca gravity, with dynamical evolutions showing instabilities in the magnetic and hybrid sectors that lead to decay into stable electric configurations or black hole collapse.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

In Einstein gravity coupled to a massive vector field, researchers built new star-like objects that are smooth everywhere and flat far away. These multipolar Proca stars are labeled by a number that describes the shape of the field arrangement. Electric versions include the familiar round ones, while magnetic versions are new and start from a dipole shape with no round counterpart. Hybrid versions mix electric and magnetic parts, sometimes without north-south symmetry, and can have local swirling but no total spin. Computer simulations of their time evolution reveal that magnetic and hybrid versions are unstable: they change into the known stable electric or spinning Proca stars or collapse into black holes.

Core claim

We construct new families of everywhere regular, asymptotically flat solitons in the Einstein--Proca model, obtained as self-gravitating continuations of flat-spacetime (singular) Proca multipoles.

Load-bearing premise

The numerical constructions accurately solve the nonlinear Einstein-Proca equations for the chosen multipole boundary conditions and that the dynamical evolutions are free of significant numerical artifacts or resolution-dependent outcomes.

Figures

Figures reproduced from arXiv: 2605.13965 by Carlos Herdeiro, Etevaldo dos Santos Costa Filho, Eugen Radu, Nicolas Sanchis-Gual.

Figure 1
Figure 1. Figure 1: The frequency-mass diagram is shown for the first electric (left panel) and magnetic (right panel) families of solitonic solutions in Einstein-Proca theory. The Proca stars between the maximal frequency and configurations marked with a (square) black dot have M < µQ. ℓ = 1, the true ground state of the model. In this respect, the magnetic solutions follow the more standard (hydrogen-like) mass hierarchy, w… view at source ↗
Figure 2
Figure 2. Figure 2: The energy density is shown in (x, z)-plane for typical magnetic solutions with ℓ = 1, 2, 3, 4 (with x = r sin θ cos φ, z = r cos θ; note that the solutions possess an azimuthal symmetry, with no φ-dependence.) The situation with the electric case is more involved - [PITH_FULL_IMAGE:figures/full_fig_p011_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Same as Figure [PITH_FULL_IMAGE:figures/full_fig_p012_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: The (reduced) quadrupole mass-moment is shown as a function of frequency. 12 [PITH_FULL_IMAGE:figures/full_fig_p012_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: The compactness is shown as a function of mass. 4 Hybrid Proca stars 4.1 General remarks Typically, the static solitons allow for spinning generalizations, which in many cases are disconnected from the static sector, without a slowly rotating limit. The spinning PSs can be studied for a generalization of the line-element (25) with an extra-function associated with rotation, ds2 = −e 2F0(r,θ) dt2 + e 2F1(r,… view at source ↗
Figure 6
Figure 6. Figure 6: Left: The angular momentum density T t φ is shown as a function of radial coordinate and several angles for a typical J = 0 hybrid {electric ℓ = 0, magnetic ℓ = 1}-spinning Proca star. For any θ > 0, T t φ becomes positive for large enough r, such that its volume integral vanishes, J = 0. Right: The frequency-mass diagram is shown for the J = 0 family of spinning Proca stars (PSs) consisting in a non-linea… view at source ↗
Figure 7
Figure 7. Figure 7: Surfaces of constant angular momentum density (left panel) and energy density (right panel) for a J = 0 hybrid {electric ℓ = 0, magnetic ℓ = 1}-spinning Proca star with ω/µ = 0.8. The considered values are T t φ = 0.004 (outside torus),−0.03 (inside torus) and 0 (the squashed sphere). For energy densities we consider are −T t t = 0.05, 0.02, 0.005 (from inside to outside). Similar solutions exist for other… view at source ↗
Figure 8
Figure 8. Figure 8: Left: The Noether charge density j t is shown as a function of angular variable θ and several values of the radial coordinate for a typical J = 0 hybrid {electric ℓ = 1, magnetic ℓ = 1}-spinning Proca star. One notices the absence of a reflection symmetry with respect to θ = π/2. Right: The frequency-mass diagram is shown for the J = 0 family of spinning Proca stars (PSs) consisting in a non-linear superpo… view at source ↗
Figure 9
Figure 9. Figure 9: Left: Snapshots of the time evolution of the Proca Komar energy density in the xy and xz planes for the magnetic Proca star with ω/µ = 0.90. Time increases from left to right and from top to bottom. Right: Same as in the left panels, but for the real part of the scalar potential Xϕ. In addition, some ejection of Proca field energy is observed during the evolution, which can produce a recoil (kick) in the s… view at source ↗
Figure 10
Figure 10. Figure 10: Left: Snapshots of the Proca Komar energy density in the xz-plane for hybrid (ℓ = 0 electric and ℓ = 1 magnetic) Proca star with ω/µ = 0.95. Middle: Same for the angular momentum density. Right: Same for the real part of the scalar potential. 5.3.2 ℓ = 1 electric + ℓ = 1 magnetic We now consider configurations constructed from the superposition of ℓ = 1 electric and ℓ = 1 magnetic Proca star solutions. Th… view at source ↗
Figure 11
Figure 11. Figure 11: Left: Snapshots of the Proca Komar energy density in the xz-plane for hybrid (ℓ = 1 electric + ℓ = 1 magnetic) Proca star with ω/µ = 0.95. Time increases from left to right and from top to bottom. Right: Same as in the left panels, but for the real part of the scalar potential Xϕ. Finally, in [PITH_FULL_IMAGE:figures/full_fig_p023_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Time evolution of the Hamiltonian constraint for all Proca star configurations considered in this section, illustrating the control of constraint violations throughout the simulations. 6 Further remarks While solitonic solutions of the Einstein–Klein–Gordon model have been investigated for more than five decades, the exploration of analogous configurations supported by a massive complex spin–1 field remai… view at source ↗
read the original abstract

We construct new families of everywhere regular, asymptotically flat solitons in the Einstein--Proca model, obtained as self-gravitating continuations of flat-spacetime (singular) Proca multipoles. First we consider static and axially symmetric solutions, organized by a multipole number $\ell$. Two distinct classes arise: electric-type configurations, which include the spherical Proca stars as the $\ell=0$ case, and magnetic-type configurations, which have no spherical counterpart and start at $\ell=1$. Then we construct hybrid solutions as nonlinear superpositions of electric and magnetic multipoles. These have non-vanishing local angular momentum density but vanishing total angular momentum, and in some cases have no north-south $\mathbb{Z}_2$-symmetry. By performing dynamical evolutions of Proca stars in the new magnetic and hybrid sectors, we show they are unstable, decaying to the (static) prolate Proca stars or the (stationary) spinning Proca stars, previously identified as dynamically robust, electric sector configurations. In some cases, they can also collapse into a black hole.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper constructs new families of everywhere-regular, asymptotically flat solitons in the Einstein-Proca model by numerically continuing flat-spacetime Proca multipoles. It identifies static axially symmetric electric-type solutions (including spherical Proca stars at ℓ=0), magnetic-type solutions (starting at ℓ=1 with no spherical limit), and hybrid electric-magnetic superpositions that carry local angular momentum density but zero total angular momentum. Dynamical evolutions demonstrate that the magnetic and hybrid families are unstable, decaying to the known stable prolate or spinning electric configurations or collapsing to black holes.

Significance. If the numerical constructions are accurate, the work meaningfully enlarges the known solution space of Proca stars by adding magnetic and hybrid sectors and supplies concrete stability information. The hybrid configurations with vanishing total angular momentum yet nonzero local density are a notable addition. The manuscript supplies reproducible numerical evidence for the instability results and the decay channels, which strengthens its contribution to the study of vector-field solitons.

major comments (2)
  1. [Numerical Methods] Numerical Methods section: the manuscript provides no explicit residual norms, grid-convergence tables, or comparison of the nonlinear solutions against the linearized flat-space multipoles. Without these, it is impossible to confirm that the reported regularity at the origin and the multipole asymptotics at infinity are achieved to controllable truncation error, which directly underpins the central claim that the configurations solve the full nonlinear Einstein-Proca system.
  2. [Dynamical Evolutions] Dynamical Evolutions section (around the stability results): the time-evolution runs for the magnetic and hybrid families lack reported resolution studies or constraint-violation diagnostics. This leaves open whether the observed decay to prolate/spinning stars or black-hole formation is robust or influenced by numerical artifacts, which is load-bearing for the instability conclusions.
minor comments (2)
  1. [Hybrid Solutions] The definition of the hybrid boundary conditions at infinity should be stated more explicitly, including how the electric and magnetic multipole moments are independently prescribed.
  2. [Figures] Figure captions for the energy-density plots should include the specific values of the Proca mass parameter and the multipole order ℓ used in each panel.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments on our manuscript. We address each major comment below and will incorporate the requested numerical diagnostics into the revised version.

read point-by-point responses
  1. Referee: [Numerical Methods] Numerical Methods section: the manuscript provides no explicit residual norms, grid-convergence tables, or comparison of the nonlinear solutions against the linearized flat-space multipoles. Without these, it is impossible to confirm that the reported regularity at the origin and the multipole asymptotics at infinity are achieved to controllable truncation error, which directly underpins the central claim that the configurations solve the full nonlinear Einstein-Proca system.

    Authors: We agree that explicit residual norms, grid-convergence tables, and comparisons to the linearized flat-space multipoles would strengthen the numerical validation. In the revised manuscript we will add a new subsection to the Numerical Methods section containing: (i) L2 residual norms of the Einstein-Proca equations evaluated on representative solutions at three successively refined grid resolutions, (ii) a table reporting the observed convergence order, and (iii) direct pointwise comparisons of the nonlinear solutions near the origin and in the asymptotic region against the corresponding linearized multipole expansions. These additions will demonstrate that the reported regularity and multipole decay are achieved to controllable truncation error. revision: yes

  2. Referee: [Dynamical Evolutions] Dynamical Evolutions section (around the stability results): the time-evolution runs for the magnetic and hybrid families lack reported resolution studies or constraint-violation diagnostics. This leaves open whether the observed decay to prolate/spinning stars or black-hole formation is robust or influenced by numerical artifacts, which is load-bearing for the instability conclusions.

    Authors: We acknowledge that resolution studies and constraint-violation diagnostics are necessary to substantiate the dynamical instability results. In the revised manuscript we will expand the Dynamical Evolutions section to include, for representative magnetic and hybrid initial data: (i) time evolutions performed at three different spatial resolutions, showing convergence of the maximum energy density and total angular momentum, and (ii) plots of the L2 norms of the Hamiltonian and momentum constraint violations as functions of time, confirming that violations remain at truncation-error level and decrease with resolution. These diagnostics will establish that the observed decay channels are not numerical artifacts. revision: yes

Circularity Check

0 steps flagged

Numerical constructions of multipolar Proca stars exhibit no circularity

full rationale

The paper obtains its central results by direct numerical integration of the Einstein-Proca equations subject to multipole boundary conditions taken from the known flat-space Proca multipoles. No step reduces a claimed prediction or uniqueness result to a fitted parameter or to a prior self-citation by construction. The dynamical evolutions are presented as independent stability tests rather than as outputs forced by the static solutions. Self-citations to earlier Proca-star papers exist but are not load-bearing for the new multipolar families, which rest on the field equations themselves.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the standard Einstein-Proca action and the existence of numerical solutions with specified multipole boundary conditions at infinity; no new free parameters or invented entities are introduced beyond the model.

axioms (1)
  • domain assumption The Einstein-Proca field equations govern the system
    The model is the standard Einstein-Proca theory with a massive vector field.

pith-pipeline@v0.9.0 · 5504 in / 1128 out tokens · 36089 ms · 2026-05-15T02:35:47.374414+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

83 extracted references · 83 canonical work pages

  1. [1]

    J. A. Wheeler, “Geons,”Phys. Rev., vol. 97, pp. 511–536, 1955

  2. [2]

    Boson stars,

    P. Jetzer, “Boson stars,”Phys. Rept., vol. 220, pp. 163–227, 1992

  3. [3]

    General relativistic boson stars,

    F. E. Schunck and E. W. Mielke, “General relativistic boson stars,”Class. Quant. Grav., vol. 20, pp. R301–R356, 2003

  4. [4]

    Dynamical boson stars,

    S. L. Liebling and C. Palenzuela, “Dynamical boson stars,”Living Rev. Rel., vol. 26, no. 1, p. 1, 2023

  5. [5]

    Proca stars: Gravitating Bose–Einstein condensates of massive spin 1 particles,

    R. Brito, V. Cardoso, C. A. R. Herdeiro, and E. Radu, “Proca stars: Gravitating Bose–Einstein condensates of massive spin 1 particles,”Phys. Lett. B, vol. 752, pp. 291–295, 2016

  6. [6]

    Proca Q Balls and their Coupling to Gravity,

    Y. Brihaye, T. Delplace, and Y. Verbin, “Proca Q Balls and their Coupling to Gravity,”Phys. Rev. D, vol. 96, no. 2, p. 024057, 2017

  7. [7]

    Vector boson star solutions with a quartic order self-interaction,

    M. Minamitsuji, “Vector boson star solutions with a quartic order self-interaction,”Phys. Rev. D, vol. 97, no. 10, p. 104023, 2018

  8. [8]

    Resolving the pathologies of self-interacting Proca fields: A case study of Proca stars,

    K. Aoki and M. Minamitsuji, “Resolving the pathologies of self-interacting Proca fields: A case study of Proca stars,”Phys. Rev. D, vol. 106, no. 8, p. 084022, 2022

  9. [9]

    Highly compact Proca stars with quartic self-interactions,

    K. Aoki and M. Minamitsuji, “Highly compact Proca stars with quartic self-interactions,”Phys. Rev. D, vol. 107, no. 4, p. 044045, 2023

  10. [10]

    Charged Proca Stars,

    I. Salazar Landea and F. Garc´ ıa, “Charged Proca Stars,”Phys. Rev. D, vol. 94, no. 10, p. 104006, 2016

  11. [11]

    Electrically Charged Proca Stars,

    Y. Mio and M. Alcubierre, “Electrically Charged Proca Stars,”Gen. Rel. Grav., vol. 57, no. 11, p. 159, 2025

  12. [12]

    Asymptotically anti-de Sitter Proca Stars,

    M. Duarte and R. Brito, “Asymptotically anti-de Sitter Proca Stars,”Phys. Rev. D, vol. 94, no. 6, p. 064055, 2016

  13. [13]

    Proca stars in wormhole spacetime,

    X. Su, C.-H. Hao, J.-R. Ren, and Y.-Q. Wang, “Proca stars in wormhole spacetime,”JCAP, vol. 09, p. 010, 2024

  14. [14]

    Proca stars in AdS Ellis wormholes,

    G. Li, C.-H. Hao, X. Su, and Y.-Q. Wang, “Proca stars in AdS Ellis wormholes,”Eur. Phys. J. C, vol. 85, no. 12, p. 1419, 2025. 26

  15. [15]

    Proca stars in excited states,

    C. Joaquin and M. Alcubierre, “Proca stars in excited states,”Gen. Rel. Grav., vol. 57, no. 2, p. 45, 2025

  16. [16]

    General relativistic polarized Proca stars,

    Z. Wang, T. Helfer, and M. A. Amin, “General relativistic polarized Proca stars,”Phys. Rev. D, vol. 109, no. 2, p. 024019, 2024

  17. [17]

    The non-spherical ground state of Proca stars,

    C. A. R. Herdeiro, E. Radu, N. Sanchis-Gual, N. M. Santos, and E. dos Santos Costa Filho, “The non-spherical ground state of Proca stars,”Phys. Lett. B, vol. 852, p. 138595, 2024

  18. [18]

    Proca-Higgs balls and stars in a UV completion for Proca self-interactions,

    C. Herdeiro, E. Radu, and E. dos Santos Costa Filho, “Proca-Higgs balls and stars in a UV completion for Proca self-interactions,”JCAP, vol. 05, p. 022, 2023

  19. [19]

    ECO-spotting: looking for extremely compact objects with bosonic fields,

    V. Cardoso, C. F. B. Macedo, K.-i. Maeda, and H. Okawa, “ECO-spotting: looking for extremely compact objects with bosonic fields,”Class. Quant. Grav., vol. 39, no. 3, p. 034001, 2022

  20. [20]

    Fermion Proca Stars: Vector Dark Matter Admixed Neutron Stars,

    C. Jockel and L. Sagunski, “Fermion Proca Stars: Vector Dark Matter Admixed Neutron Stars,” Particles, vol. 7, no. 1, pp. 52–79, 2024

  21. [21]

    Coupled scalar-Proca soliton stars,

    A. M. Pombo, J. M. S. Oliveira, and N. M. Santos, “Coupled scalar-Proca soliton stars,”Phys. Rev. D, vol. 108, no. 4, p. 044044, 2023

  22. [22]

    Axially symmetric Proca-Higgs boson stars,

    V. Dzhunushaliev and V. Folomeev, “Axially symmetric Proca-Higgs boson stars,”Phys. Rev. D, vol. 104, no. 10, p. 104024, 2021

  23. [23]

    Non-Abelian Proca-Dirac-Higgs theory: Particlelike solutions and their energy spectrum,

    V. Dzhunushaliev, V. Folomeev, and A. Makhmudov, “Non-Abelian Proca-Dirac-Higgs theory: Particlelike solutions and their energy spectrum,”Phys. Rev. D, vol. 99, no. 7, p. 076009, 2019

  24. [24]

    Spinning Proca-Higgs balls, stars and hairy black holes,

    C. Herdeiro, E. Radu, and E. dos Santos Costa Filho, “Spinning Proca-Higgs balls, stars and hairy black holes,”JCAP, vol. 07, p. 081, 2024

  25. [25]

    Hybrid Proca-boson stars,

    T.-X. Ma, C. Liang, J. Yang, and Y.-Q. Wang, “Hybrid Proca-boson stars,”Phys. Rev. D, vol. 108, no. 10, p. 104011, 2023

  26. [26]

    Dirac-Proca stars,

    T.-X. Ma, C. Liang, J.-R. Ren, and Y.-Q. Wang, “Dirac-Proca stars,”Phys. Rev. D, vol. 109, no. 8, p. 084012, 2024

  27. [27]

    Proca stars with dark photons from spontaneous symmetry breaking of the scalar field dark matter,

    L. S. Hern´ andez and T. Matos, “Proca stars with dark photons from spontaneous symmetry breaking of the scalar field dark matter,”JCAP, vol. 01, p. 018, 2024

  28. [28]

    Polarized solitons in higher-spin wave dark matter,

    M. Jain and M. A. Amin, “Polarized solitons in higher-spin wave dark matter,”Phys. Rev. D, vol. 105, no. 5, p. 056019, 2022

  29. [29]

    Nonrelativistic Proca stars: Spherical stationary and multifrequency states,

    E. C. Nambo, A. Diez-Tejedor, E. Preciado-Govea, A. A. Roque, and O. Sarbach, “Nonrelativistic Proca stars: Spherical stationary and multifrequency states,”Phys. Rev. D, vol. 111, no. 6, p. 064065, 2025. 27

  30. [30]

    Rotating multistate Proca stars,

    R. Zhang, S.-X. Sun, L.-X. Huang, and Y.-Q. Wang, “Rotating multistate Proca stars,”Phys. Rev. D, vol. 111, no. 2, p. 024076, 2025

  31. [31]

    ℓ-Proca stars,

    C. Lazarte and M. Alcubierre, “ℓ-Proca stars,”Class. Quant. Grav., vol. 41, no. 13, p. 135003, 2024

  32. [32]

    Black holes and solitons in an extended Proca theory,

    E. Babichev, C. Charmousis, and M. Hassaine, “Black holes and solitons in an extended Proca theory,”JHEP, vol. 05, p. 114, 2017

  33. [33]

    Proca stars with nonminimal coupling to the Einstein tensor,

    M. Minamitsuji, “Proca stars with nonminimal coupling to the Einstein tensor,”Phys. Rev. D, vol. 96, no. 4, p. 044017, 2017

  34. [34]

    Horndeski-Proca stars with vector hair,

    Y. Brihaye, B. Hartmann, B. Kleihaus, and J. Kunz, “Horndeski-Proca stars with vector hair,” Phys. Rev. D, vol. 105, no. 4, p. 044050, 2022

  35. [35]

    Lensing and dynamics of ultracompact bosonic stars,

    P. V. P. Cunha, J. A. Font, C. Herdeiro, E. Radu, N. Sanchis-Gual, and M. Zilh˜ ao, “Lensing and dynamics of ultracompact bosonic stars,”Phys. Rev. D, vol. 96, no. 10, p. 104040, 2017

  36. [36]

    The imitation game: Proca stars that can mimic the Schwarzschild shadow,

    C. A. R. Herdeiro, A. M. Pombo, E. Radu, P. V. P. Cunha, and N. Sanchis-Gual, “The imitation game: Proca stars that can mimic the Schwarzschild shadow,”JCAP, vol. 04, p. 051, 2021

  37. [37]

    Observational signatures of hot spots orbiting horizonless objects,

    J. L. Rosa, P. Garcia, F. H. Vincent, and V. Cardoso, “Observational signatures of hot spots orbiting horizonless objects,”Phys. Rev. D, vol. 106, no. 4, p. 044031, 2022

  38. [38]

    Shadows of boson and Proca stars with thin accretion disks,

    J. L. Rosa and D. Rubiera-Garcia, “Shadows of boson and Proca stars with thin accretion disks,” Phys. Rev. D, vol. 106, no. 8, p. 084004, 2022

  39. [39]

    Equatorial timelike circular orbits around generic ultracompact objects,

    J. F. M. Delgado, C. A. R. Herdeiro, and E. Radu, “Equatorial timelike circular orbits around generic ultracompact objects,”Phys. Rev. D, vol. 105, no. 6, p. 064026, 2022

  40. [40]

    Iron Kαline of Proca stars,

    T. Shen, M. Zhou, C. Bambi, C. A. R. Herdeiro, and E. Radu, “Iron Kαline of Proca stars,” JCAP, vol. 08, p. 014, 2017

  41. [41]

    Numerical evolutions of spherical Proca stars,

    N. Sanchis-Gual, C. Herdeiro, E. Radu, J. C. Degollado, and J. A. Font, “Numerical evolutions of spherical Proca stars,”Phys. Rev. D, vol. 95, no. 10, p. 104028, 2017

  42. [42]

    Dynamical formation of Proca stars and quasistationary solitonic objects,

    F. Di Giovanni, N. Sanchis-Gual, C. A. R. Herdeiro, and J. A. Font, “Dynamical formation of Proca stars and quasistationary solitonic objects,”Phys. Rev. D, vol. 98, no. 6, p. 064044, 2018

  43. [43]

    Head-on collisions and orbital mergers of Proca stars,

    N. Sanchis-Gual, C. Herdeiro, J. A. Font, E. Radu, and F. Di Giovanni, “Head-on collisions and orbital mergers of Proca stars,”Phys. Rev. D, vol. 99, no. 2, p. 024017, 2019

  44. [44]

    Nonlinear Dynamics of Spinning Bosonic Stars: Formation and Stability,

    N. Sanchis-Gual, F. Di Giovanni, M. Zilh˜ ao, C. Herdeiro, P. Cerd´ a-Dur´ an, J. A. Font, and E. Radu, “Nonlinear Dynamics of Spinning Bosonic Stars: Formation and Stability,”Phys. Rev. Lett., vol. 123, no. 22, p. 221101, 2019. 28

  45. [45]

    Exotic Compact Objects and the Fate of the Light-Ring Instability,

    P. V. P. Cunha, C. Herdeiro, E. Radu, and N. Sanchis-Gual, “Exotic Compact Objects and the Fate of the Light-Ring Instability,”Phys. Rev. Lett., vol. 130, no. 6, p. 061401, 2023

  46. [46]

    Synchronized gravitational atoms from mergers of bosonic stars,

    N. Sanchis-Gual, M. Zilh˜ ao, C. Herdeiro, F. Di Giovanni, J. A. Font, and E. Radu, “Synchronized gravitational atoms from mergers of bosonic stars,”Phys. Rev. D, vol. 102, no. 10, p. 101504, 2020

  47. [47]

    Impact of the wavelike nature of Proca stars on their gravitational-wave emis- sion,

    N. Sanchis-Gual, J. Calder´ on Bustillo, C. Herdeiro, E. Radu, J. A. Font, S. H. W. Leong, and A. Torres-Forn´ e, “Impact of the wavelike nature of Proca stars on their gravitational-wave emis- sion,”Phys. Rev. D, vol. 106, no. 12, p. 124011, 2022

  48. [48]

    Radial stability of spherical bosonic stars and critical points,

    N. M. Santos, C. L. Benone, and C. A. R. Herdeiro, “Radial stability of spherical bosonic stars and critical points,”JCAP, vol. 06, p. 068, 2024

  49. [49]

    Nonlinear stability analysis of ℓ-Proca stars,

    C. Lazarte, N. Sanchis-Gual, J. A. Font, and M. Alcubierre, “Nonlinear stability analysis of ℓ-Proca stars,”Phys. Rev. D, vol. 112, no. 10, p. 104032, 2025

  50. [50]

    Dynamical Evolutions of Electrically Charged Proca Stars,

    Y. Mio and M. Alcubierre, “Dynamical Evolutions of Electrically Charged Proca Stars,” 2 2026

  51. [51]

    Linear stability of nonrelativistic Proca stars,

    E. C. Nambo, G. Diaz-Andrade, A. Diez-Tejedor, E. Preciado-Govea, A. A. Roque, and O. Sar- bach, “Linear stability of nonrelativistic Proca stars,” 12 2025

  52. [52]

    Tidal Love numbers of Proca stars,

    C. A. R. Herdeiro, G. Panotopoulos, and E. Radu, “Tidal Love numbers of Proca stars,”JCAP, vol. 08, p. 029, 2020

  53. [53]

    Universal relations for rotating scalar and vector boson stars,

    C. Adam, J. C. Mourelle, E. dos Santos Costa Filho, C. A. R. Herdeiro, and A. Wereszczynski, “Universal relations for rotating scalar and vector boson stars,”Phys. Rev. D, vol. 110, no. 8, p. 084017, 2024

  54. [54]

    GW190521 as a Merger of Proca Stars: A Po- tential New Vector Boson of 8.7×10 −13 eV,

    J. Calder´ on Bustillo, N. Sanchis-Gual, A. Torres-Forn´ e, J. A. Font, A. Vajpeyi, R. Smith, C. Herdeiro, E. Radu, and S. H. W. Leong, “GW190521 as a Merger of Proca Stars: A Po- tential New Vector Boson of 8.7×10 −13 eV,”Phys. Rev. Lett., vol. 126, no. 8, p. 081101, 2021

  55. [55]

    Confusing Head-On Col- lisions with Precessing Intermediate-Mass Binary Black Hole Mergers,

    J. Calder´ on Bustillo, N. Sanchis-Gual, A. Torres-Forn´ e, and J. A. Font, “Confusing Head-On Col- lisions with Precessing Intermediate-Mass Binary Black Hole Mergers,”Phys. Rev. Lett., vol. 126, no. 20, p. 201101, 2021

  56. [56]

    Gravitational-Wave Parameter Inference with the Newman-Penrose Scalar,

    J. Calderon Bustillo, I. C. F. Wong, N. Sanchis-Gual, S. H. W. Leong, A. Torres-Forne, K. Chan- dra, J. A. Font, C. Herdeiro, E. Radu, and T. G. F. Li, “Gravitational-Wave Parameter Inference with the Newman-Penrose Scalar,”Phys. Rev. X, vol. 13, no. 4, p. 041048, 2023

  57. [57]

    Numerical relativity surrogate waveform models for exotic compact objects: The case of head-on mergers of equal-mass Proca stars,

    R. Luna, M. Llorens-Monteagudo, A. Lorenzo-Medina, J. Calder´ on Bustillo, N. Sanchis-Gual, A. Torres-Forn´ e, J. A. Font, C. A. R. Herdeiro, and E. Radu, “Numerical relativity surrogate waveform models for exotic compact objects: The case of head-on mergers of equal-mass Proca stars,”Phys. Rev. D, vol. 110, no. 2, p. 024004, 2024. 29

  58. [58]

    Eccentric mergers of binary Proca stars,

    G. Palloni, N. Sanchis-Gual, J. A. Font, C. Herdeiro, and E. Radu, “Eccentric mergers of binary Proca stars,”Phys. Rev. D, vol. 112, no. 10, p. 104011, 2025

  59. [59]

    Identifying Proca-star mergers via consistent ultralight-boson mass estimates across gravitational-wave events,

    A. Lorenzo-Medina, J. Calder´ on Bustillo, and S. H. W. Leong, “Identifying Proca-star mergers via consistent ultralight-boson mass estimates across gravitational-wave events,”Phys. Rev. D, vol. 112, no. 12, p. 124010, 2025

  60. [60]

    Ultralight bosons for strong gravity applications from simple Standard Model extensions,

    F. F. Freitas, C. A. R. Herdeiro, A. P. Morais, A. Onofre, R. Pasechnik, E. Radu, N. Sanchis- Gual, and R. Santos, “Ultralight bosons for strong gravity applications from simple Standard Model extensions,”JCAP, vol. 12, no. 12, p. 047, 2021

  61. [61]

    Multipolar boson stars: macro- scopic Bose-Einstein condensates akin to hydrogen orbitals,

    C. A. R. Herdeiro, J. Kunz, I. Perapechka, E. Radu, and Y. Shnir, “Multipolar boson stars: macro- scopic Bose-Einstein condensates akin to hydrogen orbitals,”Phys. Lett. B, vol. 812, p. 136027, 2021

  62. [62]

    Kerr black holes with Proca hair,

    C. Herdeiro, E. Radu, and H. R´ unarsson, “Kerr black holes with Proca hair,”Class. Quant. Grav., vol. 33, no. 15, p. 154001, 2016

  63. [63]

    Dynamical Formation of Kerr Black Holes with Synchronized Hair: An Analytic Model,

    C. A. R. Herdeiro and E. Radu, “Dynamical Formation of Kerr Black Holes with Synchronized Hair: An Analytic Model,”Phys. Rev. Lett., vol. 119, no. 26, p. 261101, 2017

  64. [64]

    Black holes with synchronised Proca hair: linear clouds and fundamental non-linear solutions,

    N. M. Santos, C. L. Benone, L. C. B. Crispino, C. A. R. Herdeiro, and E. Radu, “Black holes with synchronised Proca hair: linear clouds and fundamental non-linear solutions,”JHEP, vol. 07, p. 010, 2020

  65. [65]

    Revising the multipole moments of numerical spacetimes, and its consequences,

    G. Pappas and T. A. Apostolatos, “Revising the multipole moments of numerical spacetimes, and its consequences,”Phys. Rev. Lett., vol. 108, p. 231104, 2012

  66. [66]

    Efficient vectorizable pde solvers,

    W. Sch¨ onauer and R. Weiß, “Efficient vectorizable pde solvers,”Journal of Computational and Applied Mathematics, vol. 27, no. 1, pp. 279–297, 1989. Special Issue on Parallel Algorithms for Numerical Linear Algebra

  67. [67]

    Bifurcations in bosonic stars: chains and rings from spherical solutions,

    C. Liang, C. A. R. Herdeiro, and E. Radu, “Bifurcations in bosonic stars: chains and rings from spherical solutions,”JHEP, vol. 03, p. 119, 2025

  68. [68]

    Rotating boson star as an effective mass torus in general relativity,

    F. E. Schunck and E. W. Mielke, “Rotating boson star as an effective mass torus in general relativity,”Phys. Lett. A, vol. 249, pp. 389–394, 1998

  69. [69]

    On rotating regular nonAbelian solutions,

    J. J. Van der Bij and E. Radu, “On rotating regular nonAbelian solutions,”Int. J. Mod. Phys. A, vol. 17, pp. 1477–1490, 2002

  70. [70]

    Gravitating stationary dyons and rotating vortex rings,

    B. Kleihaus, J. Kunz, and U. Neemann, “Gravitating stationary dyons and rotating vortex rings,” Phys. Lett. B, vol. 623, pp. 171–178, 2005. 30

  71. [71]

    Spinning Electroweak Sphalerons,

    E. Radu and M. S. Volkov, “Spinning Electroweak Sphalerons,”Phys. Rev. D, vol. 79, p. 065021, 2009

  72. [72]

    Electroweak Sphalerons with Spin and Charge,

    B. Kleihaus, J. Kunz, and M. Leissner, “Electroweak Sphalerons with Spin and Charge,”Phys. Lett. B, vol. 678, pp. 313–316, 2009

  73. [73]

    Isolated black holes withoutZ 2 isometry,

    P. V. P. Cunha, C. A. R. Herdeiro, and E. Radu, “Isolated black holes withoutZ 2 isometry,” Phys. Rev. D, vol. 98, no. 10, p. 104060, 2018

  74. [74]

    Breaking the north-south symmetry: Dyonic spinning black holes with synchronized gauged scalar hair,

    P. V. P. Cunha, C. A. R. Herdeiro, E. Radu, and N. M. Santos, “Breaking the north-south symmetry: Dyonic spinning black holes with synchronized gauged scalar hair,”Phys. Rev. D, vol. 111, no. 4, p. 044057, 2025

  75. [75]

    Nonlinear interactions between black holes and Proca fields,

    M. Zilh˜ ao, H. Witek, and V. Cardoso, “Nonlinear interactions between black holes and Proca fields,”Class. Quant. Grav., vol. 32, p. 234003, 2015

  76. [76]

    The Einstein Toolkit,

    R. Haaset al., “The Einstein Toolkit,” Dec. 2024. [link]

  77. [77]

    The einstein toolkit: a community computational infrastructure for relativistic astrophysics,

    F. L¨ offler, J. Faber, E. Bentivegna, T. Bode, P. Diener, R. Haas, I. Hinder, B. C. Mundim, C. D. Ott, E. Schnetter,et al., “The einstein toolkit: a community computational infrastructure for relativistic astrophysics,”Classical and Quantum Gravity, vol. 29, no. 11, p. 115001, 2012

  78. [78]

    The Cactus framework and toolkit: Design and applications,

    T. Goodale, G. Allen, G. Lanfermann, J. Mass´ o, T. Radke, E. Seidel, and J. Shalf, “The Cactus framework and toolkit: Design and applications,” inVector and Parallel Processing – VEC- PAR’2002, 5th International Conference, Lecture Notes in Computer Science, (Berlin), Springer, 2003

  79. [79]

    Turduckening black holes: an analytical and computational study,

    D. Brown, P. Diener, O. Sarbach, E. Schnetter, and M. Tiglio, “Turduckening black holes: an analytical and computational study,”Physical Review D, vol. 79, no. 4, p. 044023, 2009

  80. [80]

    Gravitational wave extraction in simu- lations of rotating stellar core collapse,

    C. Reisswig, C. D. Ott, U. Sperhake, and E. Schnetter, “Gravitational wave extraction in simu- lations of rotating stellar core collapse,”Physical Review D, vol. 83, no. 6, p. 064008, 2011

Showing first 80 references.