Observational Signatures of Modified Bardeen Black Hole: Shadow and Strong Gravitational Lensing

This paper is devoted to studying the observational signatures modified by Bardeen black hole via shadow and strong lensing observations. Influence of the modified Bardeen black hole parameters q, g, and the parameter $\mu$ on the shadow radius of the black hole have been investigated numerically and graphically. Recently, EHT collaboration observed the image and shadow of supermassive black holes $M87^*$ and $SgrA^*$ where the shadow angular diameter $\theta_d=42\pm3$ for $M87^*$ and $\theta_d=51.8\pm2.3$ for $SgrA^*$. The modified black hole parameters q and $\mu$ for the fixed value of g have been constrained by the EHT collaboration data for the angular shadow diameter of $M87^*$ and $SgrA^*$. It has been observed that the constrain ranges of the parameters $\mu$ and $q$ of modified Bardeen black hole as $-0.89\leq \mu/8M^2 \leq 0.4$ and $0\leq |q|\leq 0.185$ for $M87^*$; and $-1.38\leq \mu/8M^2 \leq 0.1$ and $0\leq |q|\leq 0.058$ for $SgrA^*$, keeping the fixed value $g/2M=0.2$. Modified Bardeen black holes with the additional parameters $\mu$,$g$ and $q$ besides the mass M of the black hole as the supermassive black holes $M87^*$ and $SgrA^*$; and it is observed that to be a viable astrophysical black hole candidate. Furthermore, Gravitational lensing in the strong field limit for modified Bardeen black hole has been investigated numerically as well as graphically and compared to the other ordinary astrophysical black hole such as Schwarzschild ($\mu=\&q=0$) and regular Bardeen ($\mu=0$) black hole.Comment: 20 pages, 30 figure

Cosmological Tests of f(R,G,T)f(R,G,\mathcal{T}) Dark Energy Model in FRW Universe

This research article presents a new cosmological model formulated within the $f(R,G,\mathcal{T})$ framework, focusing on the observational signatures and parameter constraints of the model. The Markov Chain Monte Carlo (MCMC) technique is employed to effectively explore the parameter space using data from 36 Cosmic Chronometers and 1701 Pantheon Plus data points. A comparative analysis is conducted between the proposed $f(R,G,\mathcal{T})$ model and the widely accepted $\Lambda$CDM model, considering various cosmological parameters, such as Deceleration, Snap, and Jerk. By evaluating these parameters, valuable insights into the dynamics and evolution of the universe within the context of the new model are obtained. Diagnostic tests including Statefinder and Om Diagnostic are performed to further investigate the behavior and consistency of the $f(R,G,\mathcal{T})$ model. These tests provide deeper insights into the properties of the model and its compatibility with observational data. The model is subjected to statistical analysis using Information Criteria to rigorously assess its goodness of fit to the data. This analysis helps determine the level of agreement between the $f(R,G,\mathcal{T})$ model and the observational data, establishing the viability and reliability of the proposed cosmological framework. The results highlight the potential of the $f(R,G,\mathcal{T})$ framework in understanding the fundamental aspects of the universe's evolution and dynamics. The comparative analysis with the $\Lambda$CDM model, along with the comprehensive diagnostic tests performed, demonstrates the efficacy and validity of the $f(R,G,\mathcal{T})$ model in explaining observed cosmological phenomena. These findings contribute to the ongoing pursuit of accurate and comprehensive models that provide a deeper understanding of the nature of our universe.Comment: 19 pages, 10 figures; accepted for publication in EPJ

Exploring Tidal Force Effects and Shadow Constraints for Schwarzschild-like Black Hole in Starobinsky-Bel-Robinson Gravity

The current manuscript deals with the tidal force effects, geodesic deviation, and shadow constraints of the Schwarzschild-like black hole theorised in Starobinsky-Bel-Robinson gravity exhibiting M-theory compactification. In the current analysis, we explore the radial and angular tidal force effects on a radially in-falling particle by the central black hole, which is located in this spacetime. We also numerically solve the geodesic deviation equation and study the variation of the geodesic separation vector with the radial coordinate for two nearby geodesics using suitable initial conditions. All the obtained results are tested for Sag A* and M87* by constraining the value of the stringy gravity parameter $\beta$ using the shadow data from the event horizon telescope observations. All the results are compared with Schwarzschild black hole spacetime. In our study, we found that both the radial and angular tidal forces experienced by a particle switch their initial behaviour and turn compressive and stretching, respectively, before reaching the event horizon. The geodesic deviation shows an oscillating trend as well for the chosen initial condition. For the constrained value of $\beta$, we see that the spacetime geometry generated by Sag A* and M87* is effectively same for both Schwarzschild and Starobinsky-Bel-Robinson black hole. Furthermore, we also calculated the angular diameter of the shadow in Starobinsky-Bel-Robinson black hole and compared with the Schwarzschild black hole. It is observed that the angular diameter of shadow for M87* and Sgr A* in Starobinsky-Bel-Robinson black hole is smaller than the Schwarzschild black hole. The calculated results satisfy the event horizon telescope observational constraints. Finally, we have concluding remarks.Comment: 12 pages, 18 figures, accepted for publication in European Physical Journal

Which position in American Football is more likely to get you benched due to LEI? An Analysis of NFL Players injured in the years 2016-2020.

Title: Which position in American Football is more likely to get you benched due to LEI? An Analysis of NFL Players injured in the years 2016-2020. Authors: Robert de la Torre, Abdullah Sahyouni, Kinan Sawar, Gautham Pavar, Cris J. Diaz Alvarenga, Shravan Morisetty, Justin Bennie, Bohdan Matsko, Niyaz Uddin, Olivia Pakula Introduction: In American Football, there are twenty-four different positional roles that a player may assume. Some positions are unique to offense, such as quarterback and wide receiver. Others are unique to defense, such as cornerback or linebacker. There are also unique positions such as kicker or punter. All of these positions have different roles on the field and thus, different kinesiological patterns. These differences may lead to a variation in LE injuries experienced by players in different positions. Due to the prevalence of LEI\u27s in the NFL, we wanted to look at the trends for different injuries to see if there is positional correlation. Methods: We examined the NFL’s weekly injury reports for seasons from 2016 to 2020, and recorded players with four different categories of lower extremity injuries (LEI): (Hamstring, Calves, Groin, or Quadricep). Both the positional data and the nature of the injury are presented on NFL.com. We are looking at the frequency of various injuries in relation to position, as well as injury timelines for the four different LE injury categories. Results: Data is available and pending analysis. Discussion: The data collected from this study may be beneficial for any athlete engaging in organized football. Individuals with a certain injury history can be made aware of the impact their specific roles on the field may have on their injury. This can be useful information for parents and coaching staff/trainers to be aware of. Injuries to key players can dramatically impede a football season\u27s success in both monetary and subjective terms

Occurrence and Characterization of Methicillin Resistant Staphylococcus aureus in Processed Raw Foods and Ready-to-Eat Foods in an Urban Setting of a Developing Country

Infections by methicillin-resistant Staphylococcus aureus (MRSA) are gradually increasing in the community. In this study, we investigated a total of 162 food samples including 112 ready-to-eat (RTE) foods and 40 processed raw meat and fish samples collected from retail vendors in Dhaka, Bangladesh and determined the occurrence of toxigenic S. aureus and MRSA. Around 22% of samples were positive for S. aureus, RTE foods being more positive (23%) than the processed raw meat/fish samples (18%). Among 35 S. aureus isolates, 74% were resistant to erythromycin, 49% to ciprofloxacin and around 30% to oxacillin and cefoxitin. Around 37% of isolates were resistant to ≥3 classes of antibiotics and 26% of isolates (n = 9) were identified as MRSA. Majority of the isolates were positive for enterotoxin genes (74%), followed by pvl gene (71%), toxic shock syndrome toxin (tsst) gene (17%) and exfoliative toxin genes (11%). Multi locus sequence typing (MLST) of 9 MRSA isolates identified four different types such as ST80 (n = 3), ST6 (n = 2), ST239 (n = 2) and ST361 (n = 2). spa typing of MRSA isolates revealed seven different types including t1198 (n = 2), t315 (n = 2), t037 (n = 1), t275 (n = 1), t304 (n = 1), t8731 (n = 1) and t10546 (n = 1). To our knowledge, this is the first report entailing baseline data on the occurrence of MRSA in RTE foods in Dhaka highlighting a potential public health risk to street food consumers

Gravitational Lensing of Acoustic Charged Black Holes

We study the gravitational lensing of acoustic charged black holes in strong and weak field limit approximations. For this purpose, we first numerically obtain the deflection limit coefficients and deflection angle in the strong field limit. We observe that the strong deflection angle α _D increases with increasing magnitude of the charged parameter Q and that the strong deflection angle α _D of an acoustic charged black hole with tuning parameter ξ = 4 is greater than that of a standard Reissner–Nordström black hole ( ξ = 0). We also study the astrophysical consequences via strong gravitational lensing by taking the example of various supermassive black holes in the center of several galaxies and observe that the acoustic charged black hole could be quantitatively distinguished from standard Reissner–Nordström ( ξ = 0) and standard Schwarzschild ( ξ = 0, Q = 0) black holes. Furthermore, by using the Gauss–Bonnet theorem, we derive the weak deflection angle in the background of an acoustic charged black hole in the curved spacetime. We find that, for fixed values of the charged parameter Q and the tuning parameter ( ξ = 0 or 4), the weak deflection angle σ _D decreases with the impact parameter b . We also observe that the weak deflection angle σ _D decreases with increasing magnitude of the charged parameter Q for a fixed value of the tuning parameter ( ξ = 0 or 4). Our results suggest that the observational test for an acoustic charged black hole is indeed feasible, and it is generalized to the cases of acoustic Schwarzschild ( Q = 0), standard Reissner–Nordström ( ξ = 0), and standard Schwarzschild ( ξ = 0, Q = 0) black holes

Cosmological tests of

The paper is devoted to study the observational signatures of $$f(R,G,\mathcal {T})$$ gravity in FRW universe. In this research article, we present a new cosmological model formulated within the $$f(R,G,\mathcal {T})$$ framework. To constrain the model parameters, we employ the Markov Chain Monte Carlo (MCMC) technique, which enables us to explore the parameter space effectively, and used the 36 points of cosmic chronometers and 1701 points from Pantheon Plus data. We compare our proposed $$f(R,G,\mathcal {T})$$ model with the widely accepted $$\Lambda$$CDM model, considering different cosmological parameters, including deceleration, snap, and jerk. By evaluating these parameters, we gain valuable insights into the dynamics and evolution of the universe within the context of our new model. Moreover, various diagnostic tests have been conducted, such as Statefinder and Om diagnostic, to further investigate the behavior and consistency of our $$f(R,G,\mathcal {T})$$ model. These tests offer deeper insights into the properties of our model and its compatibility with observational data. We subject our model to statistical analysis using Information Criteria, which serves as a rigorous quantitative assessment of the model’s goodness of fit to the data. This analysis aids in determining the level of agreement between our $$f(R,G,\mathcal {T})$$ model and the observational data, thus establishing the viability and reliability of our proposed cosmological framework. Our findings highlight the potential of the $$f(R,G,\mathcal {T})$$ framework in understanding the fundamental aspects of the universe’s evolution and dynamics. The comparative analysis with $$\Lambda$$CDM, as well as the comprehensive diagnostic tests performed, demonstrate the efficacy and validity of our model in explaining the observed cosmological phenomena. These results contribute to the ongoing pursuit of accurate and comprehensive models that can provide a deeper understanding of the nature of our universe

Exploring tidal force effects and shadow constraints for Schwarzschild-like black hole in Starobinsky–Bel-Robinson gravity

Abstract The current manuscript deals with the tidal force effects, geodesic deviation, and shadow constraints of the Schwarzschild-like black hole theorised in Starobinsky–Bel-Robinson gravity exhibiting M-theory compactification. In the current analysis, we explore the radial and angular tidal force effects on a radially in-falling particle by the central black hole, which is located in this spacetime. We also numerically solve the geodesic deviation equation and study the variation of the geodesic separation vector with the radial coordinate for two nearby geodesics using suitable initial conditions. All the obtained results are tested for Sag A* and M87* by constraining the value of the stringy gravity parameter $$\beta$$ β using the shadow data from the event horizon telescope observations. All the results are compared with Schwarzschild black hole spacetime. In our study, we found that both the radial and angular tidal forces experienced by a particle switch their initial behaviour and turn compressive and stretching, respectively, before reaching the event horizon. The geodesic deviation shows an oscillating trend as well for the chosen initial condition. For the constrained value of $$\beta$$ β , we see that the spacetime geometry generated by Sag A* and M87* is effectively same for both Schwarzschild and Starobinsky–Bel-Robinson black hole. Furthermore, we also calculated the angular diameter of the shadow in Starobinsky–Bel-Robinson black hole and compared with the Schwarzschild black hole. It is observed that the angular diameter of shadow for M87* and Sgr A* in Starobinsky–Bel-Robinson black hole is smaller than the Schwarzschild black hole. The calculated results satisfy the event horizon telescope observational constraints