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"This book explores the subject in the context of quantum gravity. A novel approach to uncover the dark faces of the standard model of cosmology. The possibility that dark energy and dark matter are manifestations of the inhomogeneous geometry of our universe. On the history of cosmological model building and the general architecture of cosmological modes. Illustrations on the large scale structure of the universe. A new perspective on the classical static Einstein cosmos. Global properties of world models including their topology. The arrow of time in a universe with a positive cosmological constant. Exploring the consequences of a fundamental cosmological constant for our universe. Exploring why the current observed acceleration of the universe may not be its final destiny. Demonstrating that nature forbids the existence of a pure cosmological constant. Our current understanding of the long term (in time scales that greatly exceed the current age of the universe) future of the universe. And the long term fate and eventual destruction of the astrophysical objects that populate the universe, including clusters, galaxies, stars, planets, and black holes."

"Menguji validitas relativitas umum dapat dilakukan dengan memodifikasinya untuk mencari penyimpangan. Beberapa teori gravitasi termodifikasi menghasilkan potensial gravitasi dengan suku eksponensial yang menyerupai potensial Yukawa untuk aproksimasi medan lemah. Walaupun pengujian eksperimental dari koreksi Yukawa masih terbatas pada skala sistem tata surya, beberapa penelitian terbaru telah menggunakan data dari kurva rotasi galaksi untuk membatasi parameter Yukawa ini secara observasional, namun dengan asumsi bahwa barion terkopel secara lemah dengan gravitasi untuk memenuhi batasan gravitasi lokal. Studi kami mengabaikan asumsi ini dan menganalisis suku koreksi Yukawa baik dalam halo materi gelap maupun komponen bariyonik. Kami menyelidiki empat model: Newton, Almeida, MG, dan MG Duo, berdasarkan keberadaan suku koreksi Yukawa dalam komponennya dan kopling antar jenis partikel. Kami menguji keempat model ini pada tiga set data yang berbeda dari galaksi Bima Sakti, termasuk data Sofue (2015, 2017, dan 2020) dan data kurva rotasi dari Gaia DR3 oleh Wang (2023) dan Zhou (2023). Kami menemukan dukungan statistik yang kuat melalui faktor Bayes untuk model MG Duo yang menunjukkan kopling terpisah antara baryon-baryon dan baryon-DM. Namun, data observasional yang lebih tepat yang mencakup rentang radius galaksi yang lebih luas masih diperlukan untuk meningkatkan pemahaman tentang modifikasi di wilayah dalam galaksi Bima Sakti.

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Testing the validity of general relativity can be done by modifying it to search for potential deviations. Several modified gravity theories introduce a Yukawa-like exponential term in the gravitational potential for weak-field limits. While experimental tests of the Yukawa-correction are limited to Solar system scales, recent studies have used galactic rotation curve data to observationally constrain these Yukawa parameters, although assuming that baryons are weakly coupled to gravity to satisfy local gravity constraints. In our study, we relax this assumption and analyze the Yukawa-correction in both dark matter halo and baryonic components. We investigate four models: Newtonian, Almeida, MG and MG Duo models, based on the presence of the Yukawa-correction term in the components and the coupling between particle species. We tested these models on three Milky Way datasets: Sofue (2015, 2017, 2020) and rotation curves by Wang (2023) and Zhou (2023) derived from Gaia DR3 data. We find strong statistical favor through the Bayes factor for the MG Duo model that presents a separated coupling between baryon-baryon and baryon-DM. However, more precise observational data covering a broader range of galactic radii is still required to enhance our understanding of modifications in the inner regions of the Milky Way."

"A major outstanding problem in physics is understanding the nature of the dark energy that is driving the accelerating expansion of the Universe. This thesis makes a significant contribution by demonstrating, for the first time, using state-of-the-art computer simulations, that the interpretation of future galaxy survey measurements is far more subtle than is widely assumed, and that a major revision to our models of these effects is urgently needed. The work contained in the thesis was used by the WiggleZ dark energy survey to measure the growth rate of cosmic structure in 2011 and had a direct impact on the design of the surveys to be conducted by the European Space Agency's Euclid mission, a 650 million euro project to measure dark energy."

"This is the story of one of the most remarkable figures of our time - Professor Stephen Hawking, the Cambridge genius who has earned an international reputation as the most brilliant theoretical physicist since Einstein. This is not quite a biography; it is more the story of one man's quest to find the 'Theory of Everything'. Stephen Hawking's life and work have produced a multitude of amazing paradoxes: beginnings may be endings, two great scientific theories taken together may seem to give us nonsense, empty space isn't empty, and black holes aren't black. Cruel circumstances can lead to happiness, and fame and success may not. A man whose appearance inspires shock and pity takes us to where the boundaries of space and time ought to be - but are not. Substantially updated with new information drawn from interviews with Professor Hawking regarding his theories and personal life, together with fascinating new photographs from his early life to the present day, this is an insightful and captivating account of an extraordinary life and a brilliant mind"