Hasil Pencarian  ::  Simpan CSV :: Kembali

"Kami telah membahas fungsi partisi dari kondensasi Bose-Einstein di dalam perangkap parabola yang dinyatakan oleh persamaan Gross-Pitaevskii satu dimensi. Fungsi partisi itu sendiri dirumuskan hanya dengan meninjau semua tingkat-tingkat energi dari osilator kuantum makroskopik yang mirip seperti di dalam mekanika statistika. Solusi-solusi dari tingkat-tingkat energi untuk kasus ini dapat diturunkan dengan mengikuti metode yang menggunakan teori perturbasi bebas waktu. Pada kasus ini, persamaan Gross-Pitaevskii satu dimensi dapat diperlakukan sebagai osilator kuantum makroskopik dengan menerapkan kondisi bahwa faktor nonlinearnya sangat kecil. Selain itu, perumusan analitik untuk energi tingkat dasar dapat diperoleh dengan menggunakan metode tersebut. Namun demikian, tingkat-tingkat eksitasinya tidak diberikan secara eksplisit. Saat ini, kami melanjutkan pekerjaan sebelumnya untuk menurunkan tingkat-tingkat keadaan lainnya supaya dapat merumuskan fungsi partisi. Akan tetapi, kami tidak mendapatkan bentuk analitik dari fungsi partisi karena integral dari suku-suku nonlinear tidak dapat membentuk hubungan rekursif. Akibatnya, tidak hanya fungsi partisi tetapi juga energi bebas Helmholtz dan entropi harus dikaji ulang untuk memeriksa sifat konvergennya.

---

We have discussed the partition function of the Bose-Einstein condensation in parabolic trap associated to the one-dimensional Gross-Pitaevskii equation. The partition function itself is constructed by considering all the energy levels of the macroscopic quantum oscillator which is similar to statistical mechanics. The solutions of the energy levels for this case can be derived by pursuing the method that applies the time-independent perturbation theory. In this case, the one-dimensional Gross Pitaevskii equation can be treated as the one-dimensional macroscopic quantum oscillator on condition that the nonlinearity is very small. Moreover, the analytical expression for the ground state energy can be obtained by applying the method. However, the higher level states were not explicitly provided. In this research we followed up on the former work to derive explicitly the other states in order to formulate the partition function. However, we did not find the closed form of the partition function since the results of nonlinear term integral could not form the recursion relation. As a consequence, not only should the partition function but also the Helmholtz free energy and entropy should be reevaluated to check their convergences. "

"ABSTRAKTelah dikaji sebuah model sederhana yang menjelaskan mekanisme kompaktifikasi dimensi dengan menggunakan medan skalar Dirac-Born-Infeld pada lima dimensi. Dengan mereduksi satu dimensi, model kita hanya akan menghasilkan vacua anti de Sitter. Investigasi pada q dimensi ekstra (q lebih dari satu) juga mendapatkan hasil anti de Sitter.

---

ABSTRACTA simple model that explains mechanism of dimensional compactification using Dirac-Born-Infeld scalar field in five dimensions has been studied. By reducing the one dimension, our model will only result in the anti de Sitter vacua. Investigation on q-extra dimensions (q more than one) also gets the result anti de Sitter vacua."

"Penelitian kali ini mencoba memodelkan materi gelap yang menggumpal menjadi objek mampat yang disebut bintang gelap dengan mempertimbangkan efek temperatur. Partikel berjenis fermion, boson dan parafermion digunakan untuk memodelkan partikel gelap. Penentuan suhu bintang dilakukan dengan 2 metode yaitu: i) menganggap suhu bin- tang seragam dan ii) temperatur berubah-ubah bergantung tekanan dengan menganggap entropinya tetap. Didapati bahwa pada temeratur tidak nol, jenis partikel sangat mem- pengaruhi sifat-sifat dari bintang gelap. Pada kasus fermion, efek temperatur dan en- tropi membuat persamaan keadaannya lebih lunak dan didapatkan bintang yang memiliki massa dan radius lebih besar. Pada kasus boson, efek temperatur dan entropi tidak terlalu signifikan. Sedangkan pada kasus parafermion didapat persamaan keadaan tidak stabil dan perlu telaah lebih lanjut.

---

In this work we model dark matter that clumps into a compact object called a dark stars, the effects of temperature is considered. We use Fermi-Dirac, Bose-Einstein and Parafermion statistics to model dark matter particles. To determine the temperature of the star 2 methods are used, i) Assume the temperature is uniform throughout the star and ii) the temperature varies depending on pressure by assuming that the entropy is constant. It was found that in the case of finite temeratures, the type of particle statisticss greatly affects the properties of dark stars. In the case of fermions, the effects temperature and entropy make the equation of state(EoS) softer and have larger mass and radius. In the case of bosons, the effect of temperature and entropy is not too significant. Whereas in the case of parafermion, the results obtained unstable equations of state and need further study."

"This volume reviews conceptual conflicts at the foundations of physics now and in the past century. The focus is on the conditions and consequences of Einstein’s pathbreaking achievements that sealed the decline of the classical notions of space, time, radiation, and matter, and resulted in the theory of relativity. Particular attention is paid to the implications of conceptual conflicts for scientific views of the world at large, thus providing the basis for a comparison of the demise of the mechanical worldview at the turn of the 20th century with the challenges presented by cosmology at the turn of the 21st century. As a whole, the book is focused on the interplay between mathematical concepts and physical ideas throughout history by studying today’s scientific world and how it continues to redefine physics in the 21st century."

"Albert Einstein is synonymous with genius. From his remarkable theory of relativity and the famous equation E=​mc², to his concept of a unified field theory, no one else has contributed as much to science in the last century. As well as showing how the brilliant physicist developed his theories, 'Einstein' reveals the man behind the science, from his early years and experiments in Germany and his work at the Swiss Patent Office, to his marriages and children, as well as his role in the development of the atomic bomb and his work for civil rights groups in the United States. Drawing on new research and personal documents belonging to Einstein only recently made available, this book also includes items of rare facsimile memorabilia, to show you more than this scientist's groundbreaking theories"