Registered Data
Contents
- 1 [CT156]
- 1.1 [00240] Phantom cosmological model with observational constraints in symmetric teleparallel gravity
- 1.2 [00043] Matter-chameleon coupling in reconstructed Brans-Dicke cosmology
- 1.3 [00660] Dynamical system analysis of cosmological models in f(T,B) Gravity
- 1.4 [02441] QNMs and null-geodesics in the field of regular black holes
- 1.5 [02055] EMinv software platform for comprehensive analysis of geoscience data
[CT156]
[00240] Phantom cosmological model with observational constraints in symmetric teleparallel gravity
- Session Date & Time : 3E (Aug.23, 17:40-19:20)
- Type : Contributed Talk
- Abstract : The cosmological model of the Universe has been presented in symmetric teleparallel gravity and the parameters are constrained from the cosmological datasets. The nonmetricity function considered here contains higher power of the nonmetricity. With some algebraic manipulation the Hubble parameter has been obtained in redshift. The cosmological and geometrical parameters are obtained and constrained using the recent Hubble and Pantheon + SHOES datasets. The model shows early deceleration and late time acceleration.
- Classification : 83C15, 83D05, 83C10, Modified Gravity, Cosmological Model.
- Author(s) :
- Bivudutta Mishra (BITS-Pilani, Hyderabad Campus)
[00043] Matter-chameleon coupling in reconstructed Brans-Dicke cosmology
- Session Date & Time : 3E (Aug.23, 17:40-19:20)
- Type : Contributed Talk
- Abstract : In the present work, we studied the generalized Brans-Dicke (BD) model with a scalar field non-minimally coupled with the matter sector. We considered extended holographic Ricci dark energy $\rho_{\Lambda}=3\phi (\alpha\dot{H}+\beta H^2)$ in this BD cosmology framework, derived restrictions for BD parameter $\omega$, and observed a stronger matter-chameleon coupling. The EoS parameter behaved like quintom. We observed an increasing potential function as matter-chameleon coupling gets stronger. Also, deceleration parameter transited from decelerated to the accelerated universe phase.
- Classification : 83F05, 83C56
- Author(s) :
- Surajit Chattopadhyay (Amity University, Kolkata)
[00660] Dynamical system analysis of cosmological models in f(T,B) Gravity
- Session Date & Time : 3E (Aug.23, 17:40-19:20)
- Type : Contributed Talk
- Abstract : We analyze the cosmological solutions of $f(T,B)$ gravity using dynamical system analysis where $T$ is the torsion scalar and $B$ be the boundary term scalar. In our work, we assume two specific cosmological models. For first model, we consider $ f(T,B)=f_{0}(B^{k}+T^{m})$, where $k$ and $m$ are constants. For second model, we consider $f(T,B)=f_{0}T B$. We generate an autonomous system of differential equations for each models by introducing new dimensionless variables. To solve this system of equations, we use dynamical system analysis. We also investigate the critical points and their natures, stability conditions and their behaviors of Universe expansion. For both models, we get four critical points. The phase plots of this system are analyzed in detail and study their geometrical interpretations also. In both model, we evaluated density parameters such as $\Omega_{r}$, $\Omega_{m}$, $\Omega_{\Lambda}$ and $\omega_{eff}$ and deceleration parameter $(q)$ and find their suitable range of the parameter $\lambda$ for stability. For first model, we get $\omega_{eff}=-0.833,-0.166$ and for second model, we get $\omega_{eff}=-\frac{1}{3}$. This shows that both the models are in quintessence phase. Further, we compare the values of EoS parameter and deceleration parameter with the observational values.
- Classification : 83F05
- Author(s) :
- Sanasam Surendra Singh (National Institute of Technology Manipur)
- Amit Samaddar (National Institute of Technology Manipur)
[02441] QNMs and null-geodesics in the field of regular black holes
- Session Date & Time : 3E (Aug.23, 17:40-19:20)
- Type : Contributed Talk
- Abstract : A theoretical analysis for both null-geodesics and timelike geodesics has been investigated for regular blackholes. We determine the relationship between radius of photon sphere and shadow. We also find the relationship between null-geodesics and quasinormal mode(QNM) frequency in the eikonal approximation. The real and imaginary part of QNMs frequency determines the angular frequency and instability timescale of the circular orbit, respectively. We compute innermost stable circular orbit and marginally bound circular orbit for regular blackholes.
- Classification : 85-08, 83C15, 83C05, 83C10, 83C22
- Author(s) :
- Monimala Mondal (Jadavpur University)
- Farook Rahaman (Jadavpur University)
[02055] EMinv software platform for comprehensive analysis of geoscience data
- Session Date & Time : 3E (Aug.23, 17:40-19:20)
- Type : Contributed Talk
- Abstract : We designed and developed a new software platform, consisting of processing and inversion modular for magnetotelluric data and visualization modular for all the geoscience results. New self-improved processing and inversion algorithms were applied in this platform. This platform unified the format of data, results and models and connected data processing, interpretaion and visualization, using our new rule and integrated standard. The platform is a useful tool for both production managers and scientific researchers.
- Classification : 86-04, 86-02
- Author(s) :
- Kun Zhang (Chinese Academy of Geopogical Sciences)