Constraining the String Gauge Field by Galaxy Rotation Curves and Perihelion Precession of Planets

Abstract

We discuss a cosmological model in which the string gauge field coupled universally to matter gives rise to an extra centripetal force and will have observable signatures on cosmological and astronomical observations. Several tests are performed using data including galaxy rotation curves of twenty-two spiral galaxies of varied luminosities and sizes, and perihelion precessions of planets in the solar system. The rotation curves of the same group of galaxies are independently fit using a dark matter model with the generalized Navarro-Frenk-White (NFW) profile and the string model. Remarkable fit of galaxy rotation curves is achieved using the one-parameter string model as compared to the three-parameter dark matter model with the Navarro-Frenk-White profile. The average χ 2 value of the NFW fit is 9% better than that of the string model at a price of two more free parameters. Furthermore, from the string model, we can give a dynamical explanation for the phenomenological Tully-Fisher relation. We are able to derive a relation between field strength, galaxy size and luminosity, which can be verified with data from the 22 galaxies. To further test the hypothesis of the universal existence of the string gauge field, we apply our string model to the solar system. Constraint on the magnitude of the string field in the solar system is deduced from the current ranges for any anomalous perihelion precession of planets allowed by the latest observations. The field distribution resembles a dipole field originating from the Sun. The string field strength deduced from the solar system observations is of a similar magnitudes as the field strength needed to sustain the rotational speed of the sun inside the Milky Way. This hypothesis can be tested further by future observations with higher precision.

The MAGPI survey: Drivers of kinematic asymmetries in the ionised gas ofz∼ 0.3 star-forming galaxies

“…Our sample consists of star-forming galaxies with Sérsic indices 1, which implies we are mostly looking at late-type galaxies. Late-type galaxies often host non-axisymmetric features such as bars (Kormendy & Kennicutt 2004; Cheung et al 2013). Bars can cause gaseous inflows onto the nucleus of the galaxies, and these inflows would cause complex kinematics, particularly so for the inner regions.…”

Orbital Motions and the Conservation-Law/Preferred-Frame α3 Parameter

“…See Section 3.1 for a discussion on potential limitations and strength of such an indirect, opportunistic approach. We stress once again that an examination of the existing literature shows that such a strategy is widely adopted for preliminarily constraining several non-standard effects in the Solar System; see, e.g., the recent works [36][37][38][39][40]. Here we recall that, strictly speaking, it allows to test alternative theories of gravity differing from general relativity just for α 3 , being all the other PPN parameters set to their general relativistic values.…”

Effective apsidal precession from a monopole solution in a Zipoy spacetime

“…Since the explanation of the perihelion advance of Mercury by Einstein in 1915 as an application of general Relativity (GR), it has been considered one of the fundamental laboratories for testing extensions of standard GR and other gravitational models such as e.g, the modification of newtonian Dynamics (MOND) [2], Kaluza-Klein five-dimensional gravity [3], Yukawa-like Modified Gravity [4], Horava-Lifshitz gravity [5], brane-world models and variants [6][7][8][9][10][11][12], the parametric post-newtonian (PPN) framework and beyond, and approaches in the weak field/slow motion limits [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. As largely known, in GR, the coordinate systems are overall physically equivalents and to obtain new prospects on applications in astrophysics, the diffeomorphic a e-mail: abecapistrano@gmail.com b e-mail: paola.seidel@gmail.com c e-mail: cabral@uft.edu.br transformations cannot be allowed to happen.…”