ترغب بنشر مسار تعليمي؟ اضغط هنا

Can corrections to gravity at galactic distances be decisive to the problem of dark matter and dark energy?

110   0   0.0 ( 0 )
 نشر من قبل Timur Fianovich Kamalov
 تاريخ النشر 2021
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

Are Dark Matter and Dark Energy the result of uncalculated addition derivatives? The need to introduce dark matter dark and energy becomes unnecessary if we consider that, the phenomenon of dark matter and dark energy is a result of not computing the additional derivatives of the equation of motion. For this purpose, we use higher derivatives in the form of non-local variables, known as the Ostrogradsky formalism. As a mathematician, Ostrogradsky considered the dependence of the Lagrange function on acceleration and its higher derivatives with respect to time. This is the case that fully correspond with the real frame of reference, and that can be both inertial and non-inertial frames. The problem of dark matter and dark energy presented starting from basic observations to explain the different results in theory and experiment. The study of galactic motion, especially the rotation curves, showed that a large amount of dark matter can be found mainly in galactic halos. The search for dark matter and dark energy has not confirmed with the experimental discovery of it, so we use Ostrogradsky formalities to explain the effects described above, so that the need to introduce dark matter and dark energy disappears.

قيم البحث

اقرأ أيضاً

We propose a new scenario where dark matter belongs to a secluded sector coupled to the Standard Model through energy--momentum tensors. Our model is motivated by constructions where gravity {it emerges} from a hidden sector, the graviton being ident ified by the kinetic term of the fields in the secluded sector. Supposing that the lighter particle of the secluded sector is the dark component of the Universe, we show that we can produce it in a sufficiently large amount despite the suppressed couplings of the theory, thanks to large temperatures of the thermal bath in the early stage of the Universe.
In this work, we explore some cosmological implications of the model proposed by M. Visser in 1998. In his approach, Visser intends to take in account mass for the graviton by means of an additional bimetric tensor in the Einsteins field equations. O ur study has shown that a consistent cosmological model arises from Vissers approach. The most interesting feature is that an accelerated expansion phase naturally emerges from the cosmological model, and we do not need to postulate any kind of dark energy to explain the current observational data for distant type Ia supernovae (SNIa).
In this paper we study a model of interacting dark energy - dark matter where the ratio between these components is not constant, changing from early to late times in such a way that the model can solve or alleviate the cosmic coincidence problem (CP ). The interaction arises from an assumed relation of the form $rho_xproptorho_d^alpha$, where $rho_x$ and $rho_d$ are the energy densities of dark energy and dark matter components, respectively, and $alpha$ is a free parameter. For a dark energy equation of state parameter $w=-1$ we found that, if $alpha=0$, the standard $Lambda$CDM model is recovered, where the coincidence problem is unsolved. For $0<alpha<1$, the CP would be alleviated and for $alphasim 1$, the CP would be solved. The dark energy component is analyzed with both $w=-1$ and $w eq -1$. Using Supernovae type Ia and Hubble parameter data constraints, in the case $w=-1$ we find $alpha=0.109^{+0.062}_{-0.072}$ at 68% C.L., and the CP is alleviated. This model is also slightly favoured against nonflat $Lambda$CDM model by using a Bayesian Information Criterion (BIC) analysis. For $w eq-1$, a degeneracy arises on the $w$ - $alpha$ plane. In order to break such degeneracy we add cosmic microwave background distance priors and baryonic acoustic oscillations data to the constraints, yielding $alpha=-0.075pm 0.046$ at 68% C.L.. In this case we find that the CP is not alleviated even for 2$sigma$ interval for $alpha$. Furthermore, this last model is discarded against nonflat $Lambda$CDM according to BIC analysis.
The cosmological constant problem is the principal obstacle in the attempt to interpret dark energy as the quantum vacuum energy. We suggest that the obstacle can be removed, i.e. that the cosmological constant problem can be resolved by assuming tha t the virtual particles and antiparticles in the quantum vacuum have the gravitational charge of the opposite sign. The corresponding estimates of the cosmological constant, dark energy density and the equation of state for dark energy are in the intriguing agreement with the observed values in the present day Universe. However, our approach and the Standard Cosmology lead to very different predictions for the future of the Universe; the exponential growth of the scale factor, predicted by the Standard Cosmology, is suppressed in our model.
We discuss scenarios in which the galactic dark matter in spiral galaxies is described by a long range coherent field which settles in a stationary configuration that might account for the features of the galactic rotation curves. The simplest possib ility is to consider scalar fields, so we discuss in particular, two mechanisms that would account for the settlement of the scalar field in a non-trivial configuration in the absence of a direct coupling of the field with ordinary matter: topological defects, and spontaneous scalarization.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا