We study the dynamical system of braneworld cosmology with the effective cosmological constant as... more We study the dynamical system of braneworld cosmology with the effective cosmological constant as the effective dark energy on brane universe. Firstly we introduce several scenarios of braneworld model then derive the effective EFE on the brane which reduced at low energy limit. Next, we discuss the FRW cosmological model in braneworld scenario considered in static and non-closed system. In the dynamical study of cosmology, we assume the equation of state of dark energy varies with time and can be parameterized as a function of scale factor of the universe. Using the dynamical system approach, we describe the evolution of brane universe with non-vanishing NCC/BCC term. In this study, we investigate the effects of the presence of NCC/BCC perturbations in brane universe. Finally, we discuss the NCC/BCC perturbations in the late-time cosmic acceleration when the dark energy contribution is ΩΛ ≃ 0.72.
The dynamical system of braneworld cosmology has been studied with dark energy contribution Λ. In... more The dynamical system of braneworld cosmology has been studied with dark energy contribution Λ. In the braneworld scenario, the Einstein gravitational field equation is modified by an extra-dimensional approach. The matter fields in this scenario, are confined on the 4-dimensional spacetime (brane), while gravity acts in the full spacetime (5-dimensions). The FRW brane solutions of the effective Einstein field equation have also been derived by considering the static brane and a not closed brane system. Furthermore, the cosmological dynamics of braneworld is also studied at high energy regime and at low energy limit. In high energy approach, the dark radiation or ‘the gravitational radiation’ also dominates in the very early universe. Whereas, at low energy limit, the nonlocal bulk cosmological constant, Λ(5) has an important role, especially in the late-time cosmic acceleration with dark energy contributes about Ω(Λ) ≃ 0.7, which is assumed the equation of state for dark energy varies with time. Moreover, some effects of Λ(5) are also discussed in braneworld cosmology.
Prosiding Seminar Nasional Fisika Makassar 2019 ISBN 978-602-52468-7-6, 2020
Hasil perhitungan rapat massa kritis alam semesta berdasarkan persamaan Einstein tanpa konstanta ... more Hasil perhitungan rapat massa kritis alam semesta berdasarkan persamaan Einstein tanpa konstanta kosmologi dengan data pengamatan astronomi berbeda signifikan. Hal ini menunjukkan alam semesta mengembang dipercepat yang mengindikasikan adanya energi gelap yang mendominasi alam semesta saat ini. Oleh karena itu, dalam makalah ini dilakukan studi untuk menyelidiki energi gelap dengan model Gauss-Bonnet (GB) dan medan skalar. Hasil yang diperoleh dalam studi ini kemudian dibandingkan dengan data pengamatan astronomi.
Prosiding Seminar Nasional Fisika Makassar 2019 ISBN 978-602-52468-7-6, 2020
Telah dilakukan studi pendekatan sistem dinamis untuk menggambarkan evolusi jari-jari kelengkunga... more Telah dilakukan studi pendekatan sistem dinamis untuk menggambarkan evolusi jari-jari kelengkungan bulk Anti de-Sitter (AdS) 5D dalam kosmologi braneworld. Studi ini merupakan kelanjutan dari makalah pertama [1] (10.1088/1742-6596/1354/1/012008) yang membahas tentang kontribusi keberadaan gangguan konstanta kosmologi non-lokal (NCC) atau konstanta kosmologi bulk (BCC) pada alam semesta brane sebagai energi gelap efektif. Dalam makalah kedua ini, merujuk dari makalah yang pertama, evolusi jari-jari kelengkungan bulk AdS digambarkan sebagai efek lain dari perturbasi NCC/BCC dalam sistem dinamika kosmologi braneworld. Dalam studi ini, jari-jari kelengkungan bulk AdS 5D yang diperoleh bernilai imajiner dan besarnya sangat bergantung pada besar kontribusi gangguan NCC/BCC serta tetapan Hubble pada brane. Selain itu, juga diperoleh bahwa skala jari-jari kelengkungan bulk AdS sangat besar, yaitu $∼ 10^{26} m ∼ 10 Glyr$ pada gambaran alam semesta sekarang yang setara dengan skala jari-jari alam semesta saat ini, bahkan besarnya menuju tak-hingga. Terakhir dibahas hubungan kausalitas antara dimensi ekstra imajiner dengan alam semesta nyata termasuk juga hubungannya dengan ekspansi alam semesta dipercepat yang terjadi saat ini.
Journal of Physics: Conference Series, Volume 1354: 012008, 2019
We study the dynamical system of braneworld cosmology with the effective cosmological constant as... more We study the dynamical system of braneworld cosmology with the effective cosmological constant as the effective dark energy on brane universe. Firstly we introduce several scenarios of braneworld model then derive the effective EFE on the brane which reduced at low energy limit. Next, we discuss the FRW cosmological model in braneworld scenario considered in static and non-closed system. In the dynamical study of cosmology, we assume the equation of state of dark energy varies with time and can be parameterized as a function of scale factor of the universe. Using the dynamical system approach, we describe the evolution of brane universe with non-vanishing NCC/ BCC term. In this study, we investigate the effects of the presence of NCC/ BCC perturbations in brane universe. Finally, we discuss the NCC/ BCC perturbations in the late-time cosmic acceleration when the dark energy contribution is $\Omega_{\Lambda} \simeq 0.72$.
Prosiding Seminar Nasional Fisika - Makassar 2018: Penguatan Riset dan Pendidikan Fisika untuk Indonesia Maju, 2018
Braneworld is a model of extra-dimensional approach in modified gravity which motivated by M-theo... more Braneworld is a model of extra-dimensional approach in modified gravity which motivated by M-theory. In the braneworld scenario, a brane was described as a domain wall or a 3D hypersurface with positive tension (λ) embedded in a 5D Anti-de-Sitter bulk spacetime with $Z_2$ symmetry. Modified gravity in general relativity using braneworld model produce some additional correction terms for the Einstein field equation on the brane, which is called as the effective field equation. In this paper, we just study the braneworld cosmology at low energy limit, so that the quadratic term which relevant with high energy scale is negligible. Furthermore, we consider the nonlocal effects vanish on the brane, so the solution on the brane is a closed system. Finally, in the study of dynamical system approach of braneworld cosmology, we found the solution on the FRW brane satisfies the ΛCDM model, where the matter contributes about $\Omega_M ≃ 0.3$ and the universe is dominated by dark energy or vacuum energy, $\Omega_Λ ≃ 0.7$ at low energy limit.
Prosiding Seminar Nasional Fisika Makassar 2018: Penguatan Riset dan Pendidikan Fisika untuk Indonesia Maju, 2018
Dunia brane merupakan model pendekatan dimensi ekstra dalam gravitasi yang dimotivasi oleh teori-... more Dunia brane merupakan model pendekatan dimensi ekstra dalam gravitasi yang dimotivasi oleh teori-M. Dalam skenario dunia brane, sebuah brane digambarkan sebagai suatu dinding domain atau permukaan-hiper 4D dengan tensi positif (λ) dalam ruang-waktu bulk Anti de-Sitter 5D dengan simetri Z_2. Modifikasi gravitasi pada relativitas umum menggunakan skenario dunia brane menghasilkan beberapa suku koreksi terhadap persamaan medan Einstein pada brane yang dikenal sebagai persamaan medan “efektif”. Dalam makalah ini, kosmologi dunia brane hanya ditinjau pada limit energi rendah, sehingga medan materi pada suku kuadratik yang relevan dengan energi tinggi diabaikan. Sedangkan efek-efek non-lokal pada brane lenyap sehingga memberikan solusi pada brane sebagai sistem tertutup. Selanjutnya studi pendekatan sistem dinamik dari kosmologi dunia brane ini memberikan solusi yang memenuhi model ΛCDM, dimana kontribusi materi, Ω_M ≈ 0,3 dan alam semesta didominasi oleh kontribusi energi gelap atau energi vakum, Ω_Λ ≈ 0,7 pada limit energi rendah.
Dark energy, the mysterious cause of the accelerating expansion of the Universe, is one of the mo... more Dark energy, the mysterious cause of the accelerating expansion of the Universe, is one of the most important fields of research in astrophysics and cosmology today. Introducing the theoretical ideas, observational methods and results, this textbook is ideally suited to graduate courses on dark energy, and will also supplement advanced cosmology courses.
We study the dynamical system of braneworld cosmology with the effective cosmological constant as... more We study the dynamical system of braneworld cosmology with the effective cosmological constant as the effective dark energy on brane universe. Firstly we introduce several scenarios of braneworld model then derive the effective EFE on the brane which reduced at low energy limit. Next, we discuss the FRW cosmological model in braneworld scenario considered in static and non-closed system. In the dynamical study of cosmology, we assume the equation of state of dark energy varies with time and can be parameterized as a function of scale factor of the universe. Using the dynamical system approach, we describe the evolution of brane universe with non-vanishing NCC/BCC term. In this study, we investigate the effects of the presence of NCC/BCC perturbations in brane universe. Finally, we discuss the NCC/BCC perturbations in the late-time cosmic acceleration when the dark energy contribution is ΩΛ ≃ 0.72.
The dynamical system of braneworld cosmology has been studied with dark energy contribution Λ. In... more The dynamical system of braneworld cosmology has been studied with dark energy contribution Λ. In the braneworld scenario, the Einstein gravitational field equation is modified by an extra-dimensional approach. The matter fields in this scenario, are confined on the 4-dimensional spacetime (brane), while gravity acts in the full spacetime (5-dimensions). The FRW brane solutions of the effective Einstein field equation have also been derived by considering the static brane and a not closed brane system. Furthermore, the cosmological dynamics of braneworld is also studied at high energy regime and at low energy limit. In high energy approach, the dark radiation or ‘the gravitational radiation’ also dominates in the very early universe. Whereas, at low energy limit, the nonlocal bulk cosmological constant, Λ(5) has an important role, especially in the late-time cosmic acceleration with dark energy contributes about Ω(Λ) ≃ 0.7, which is assumed the equation of state for dark energy varies with time. Moreover, some effects of Λ(5) are also discussed in braneworld cosmology.
Prosiding Seminar Nasional Fisika Makassar 2019 ISBN 978-602-52468-7-6, 2020
Hasil perhitungan rapat massa kritis alam semesta berdasarkan persamaan Einstein tanpa konstanta ... more Hasil perhitungan rapat massa kritis alam semesta berdasarkan persamaan Einstein tanpa konstanta kosmologi dengan data pengamatan astronomi berbeda signifikan. Hal ini menunjukkan alam semesta mengembang dipercepat yang mengindikasikan adanya energi gelap yang mendominasi alam semesta saat ini. Oleh karena itu, dalam makalah ini dilakukan studi untuk menyelidiki energi gelap dengan model Gauss-Bonnet (GB) dan medan skalar. Hasil yang diperoleh dalam studi ini kemudian dibandingkan dengan data pengamatan astronomi.
Prosiding Seminar Nasional Fisika Makassar 2019 ISBN 978-602-52468-7-6, 2020
Telah dilakukan studi pendekatan sistem dinamis untuk menggambarkan evolusi jari-jari kelengkunga... more Telah dilakukan studi pendekatan sistem dinamis untuk menggambarkan evolusi jari-jari kelengkungan bulk Anti de-Sitter (AdS) 5D dalam kosmologi braneworld. Studi ini merupakan kelanjutan dari makalah pertama [1] (10.1088/1742-6596/1354/1/012008) yang membahas tentang kontribusi keberadaan gangguan konstanta kosmologi non-lokal (NCC) atau konstanta kosmologi bulk (BCC) pada alam semesta brane sebagai energi gelap efektif. Dalam makalah kedua ini, merujuk dari makalah yang pertama, evolusi jari-jari kelengkungan bulk AdS digambarkan sebagai efek lain dari perturbasi NCC/BCC dalam sistem dinamika kosmologi braneworld. Dalam studi ini, jari-jari kelengkungan bulk AdS 5D yang diperoleh bernilai imajiner dan besarnya sangat bergantung pada besar kontribusi gangguan NCC/BCC serta tetapan Hubble pada brane. Selain itu, juga diperoleh bahwa skala jari-jari kelengkungan bulk AdS sangat besar, yaitu $∼ 10^{26} m ∼ 10 Glyr$ pada gambaran alam semesta sekarang yang setara dengan skala jari-jari alam semesta saat ini, bahkan besarnya menuju tak-hingga. Terakhir dibahas hubungan kausalitas antara dimensi ekstra imajiner dengan alam semesta nyata termasuk juga hubungannya dengan ekspansi alam semesta dipercepat yang terjadi saat ini.
Journal of Physics: Conference Series, Volume 1354: 012008, 2019
We study the dynamical system of braneworld cosmology with the effective cosmological constant as... more We study the dynamical system of braneworld cosmology with the effective cosmological constant as the effective dark energy on brane universe. Firstly we introduce several scenarios of braneworld model then derive the effective EFE on the brane which reduced at low energy limit. Next, we discuss the FRW cosmological model in braneworld scenario considered in static and non-closed system. In the dynamical study of cosmology, we assume the equation of state of dark energy varies with time and can be parameterized as a function of scale factor of the universe. Using the dynamical system approach, we describe the evolution of brane universe with non-vanishing NCC/ BCC term. In this study, we investigate the effects of the presence of NCC/ BCC perturbations in brane universe. Finally, we discuss the NCC/ BCC perturbations in the late-time cosmic acceleration when the dark energy contribution is $\Omega_{\Lambda} \simeq 0.72$.
Prosiding Seminar Nasional Fisika - Makassar 2018: Penguatan Riset dan Pendidikan Fisika untuk Indonesia Maju, 2018
Braneworld is a model of extra-dimensional approach in modified gravity which motivated by M-theo... more Braneworld is a model of extra-dimensional approach in modified gravity which motivated by M-theory. In the braneworld scenario, a brane was described as a domain wall or a 3D hypersurface with positive tension (λ) embedded in a 5D Anti-de-Sitter bulk spacetime with $Z_2$ symmetry. Modified gravity in general relativity using braneworld model produce some additional correction terms for the Einstein field equation on the brane, which is called as the effective field equation. In this paper, we just study the braneworld cosmology at low energy limit, so that the quadratic term which relevant with high energy scale is negligible. Furthermore, we consider the nonlocal effects vanish on the brane, so the solution on the brane is a closed system. Finally, in the study of dynamical system approach of braneworld cosmology, we found the solution on the FRW brane satisfies the ΛCDM model, where the matter contributes about $\Omega_M ≃ 0.3$ and the universe is dominated by dark energy or vacuum energy, $\Omega_Λ ≃ 0.7$ at low energy limit.
Prosiding Seminar Nasional Fisika Makassar 2018: Penguatan Riset dan Pendidikan Fisika untuk Indonesia Maju, 2018
Dunia brane merupakan model pendekatan dimensi ekstra dalam gravitasi yang dimotivasi oleh teori-... more Dunia brane merupakan model pendekatan dimensi ekstra dalam gravitasi yang dimotivasi oleh teori-M. Dalam skenario dunia brane, sebuah brane digambarkan sebagai suatu dinding domain atau permukaan-hiper 4D dengan tensi positif (λ) dalam ruang-waktu bulk Anti de-Sitter 5D dengan simetri Z_2. Modifikasi gravitasi pada relativitas umum menggunakan skenario dunia brane menghasilkan beberapa suku koreksi terhadap persamaan medan Einstein pada brane yang dikenal sebagai persamaan medan “efektif”. Dalam makalah ini, kosmologi dunia brane hanya ditinjau pada limit energi rendah, sehingga medan materi pada suku kuadratik yang relevan dengan energi tinggi diabaikan. Sedangkan efek-efek non-lokal pada brane lenyap sehingga memberikan solusi pada brane sebagai sistem tertutup. Selanjutnya studi pendekatan sistem dinamik dari kosmologi dunia brane ini memberikan solusi yang memenuhi model ΛCDM, dimana kontribusi materi, Ω_M ≈ 0,3 dan alam semesta didominasi oleh kontribusi energi gelap atau energi vakum, Ω_Λ ≈ 0,7 pada limit energi rendah.
Dark energy, the mysterious cause of the accelerating expansion of the Universe, is one of the mo... more Dark energy, the mysterious cause of the accelerating expansion of the Universe, is one of the most important fields of research in astrophysics and cosmology today. Introducing the theoretical ideas, observational methods and results, this textbook is ideally suited to graduate courses on dark energy, and will also supplement advanced cosmology courses.
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