Pengantar teori relativitas dan kosmologi

buku ini bercerita tentang teori yang telah mengubah dunia: teori relativitas yang ditemukan oleh Einsten tahun 1905 Teori ini dibahas secara rinci, mulai dari teori relativitas umum, penerapan teori relativitas umum, teori relativitas khusus hingan penerapan teori raltivitas khusus. kecuali it, ada juga pembahasan tentang kosmologi: sejarah dan dinamika jagad raya

Pengantar Teori Relativitas dan Kosmologi

vi, 219 hlm.; 20 x 15 c

SIMULASI MODEL ISING 2D DENGAN FAKTOR MEDAN MAGNET DAN TEMPERATUR MENGGUNAKAN IMAGEJ

This research aims to simulate the two dimensional Ising spin using Monte Carlo method with Metropolis algorithm. The programs are written in macro language and ran in ImageJ software. In the absence of external magnetic field, some physical observables such as energy and magnetization are measured as functions of temperature and system size. Therefore, for a certain system size namely 128 x 128, we calculated both specific heat capacity and susceptibility as functions of temperature. We found that for low temperature regime, the absolute magnetization close to 1, which means that all spins are in the homogeneous state. By the increase the temperature close to the critical one = 2,3 J/kB, the magnetization decrease drastically into zero. For the energy, low temperature regime gives the low energy. By the increase the temperature, the energy increase drastically near the critical temperature, and finally close to zero for high temperature regime. The role of the critical temperature appears significantly indicated by both specific heat capacity and susceptibility. Both observables have very high values in the critical temperature. In the presence of the external magnetic field, we vary the magnitude of the field and measure the magnetization. We found that the hysteresis of the magnetizations appears. Later, we determine both remanent magnetization and coercive field for a certain temperature. We found that both tend to decrease by the increase of the temperature. Using the sinusoidal and square waves of the external field, we found that the profile of the magnetization is similar to that of the external field. However, we found the time lag between the two profiles. Moreover, we measure the time lag between the magnetization and the external field and reveal that time lag decrease for the increase of the amplitude of the external field

KAJIAN SIMULASI MODEL BISWAS-SEN DALAM DINAMIKA OPINI UNTUK 1 DIMENSI DENGAN PARAMETER BAK-SUHU

Pada penelitian ini model dinamika yang digunakan adalah model Biswas-Sen. Model Biswas-Sen merupakan model dinamika opini biner yang tergantung pada ukuran domain tetangga. Dalam model dinamika opini biner diasumsikan bahwa seorang individu akan dipengaruhi oleh tetangga atau domain terdekatnya. Model ini direpresentasikan oleh suatu sistem spin Ising yang hanya memiliki 2 keadaan, yaitu keadaan up dan down. Penelitian ini mengusulkan sebuah model Biswas-Sen dalam 1 dimensi dengan parameter bak-suhu (temperature-like fluctuation) untukmenguji eksistensi transisi fase. Pada model Biswas-Sen 1 dimensi tanpa parameter bak-suhu tidak terjadi transisi fase. Sehingga dalam model Biswas-Sen 1 dimensi dianalogikan seperti model Ising 1 dimensi yaitu tidak ada transisi fase. Simulasi dilakukan dengan metode Monte Carlo dengan menggunakan algoritma Metropolis dan softwareImageJ. Hasil dari penelitian ini yaitu model Biswas-Sen 1 dengan parameter bak-suhu belum muncul transisi fase. Parameter bak-suhu hanya berperan untuk menunda waktu untuk mencapai keadaan homogen dan membuat sistem cenderung disorder namun keadaan akhir yang diperoleh tetap homogen

KAJIAN DINAMIKA OPINI MENGGUNAKAN SIMULASI SPIN ISING 1 DIMENSI & 2 DIMENSI

A research on opinion dynamics (+1,�1 of system transition from a heterogeneous state to a homogeneous one using simulation of 1 dimension and 2 dimension Ising spin has been done. This study uses variations of the system size and any interactions space model, which aims to analyzes the time of homogeneous state on the system size, and define the criteria of the interaction space that can minimize time of homogeneous state. The simulations has been done by using the Software ImageJ 1,47t. Result of the analysis from time of homogeneous state on the system size is shown on the linier curve which system with the larger size indicated the larger time to reach a homogeneous state. Criteria interaction space models to minimize time of homogeneous state is 2 dimension models. This criteria of model is not determined by the wide of the interaction space

Mass media and its impact on opinion dynamics of the nonlinear qq-voter model

With the success of general conceptual frameworks of statistical physics, many scholars have tried to apply these concepts to other interdisciplinary fields, such as socio-politics, economics, biology, medicine, and many more. In this work, we study the effect of mass media on opinion evolution based on the nonlinear $q$-voter by mean with probability $p$ a voter adopts the mass media opinion whenever a $q$-sized agent in the population is in unanimous agreement (have the same opinion). We perform analytical and numerical calculations for some quantities of macroscopic parameters of the model such as order parameter (representing an average of public opinion), consensus (relaxation) time, and exit probability, and obtain the agreement results. We find the power-law relations for some quantities of the model. (1) The probability threshold $p_t$, i.e a probability that makes the system reaches a homogeneous state, follows the power-law relation $p_t \sim q^{\gamma}$ with the $q$-sized agent, where $\gamma = -1.00 \pm 0.01$ is the best fitting parameter. The probability threshold $p_t$ also eliminates the standard phase transition of the model. (2) The relaxation or consensus time (which is the time needed by the system to reach consensus) $\tau$ with the population size $N$ is obtained in the form of $\tau \sim N^{\delta}$, where $\delta$ depends on the probability $p$ and $q$-sized agent. We also approximate the critical point $r_c$ and the system's scaling parameters by employing the standard finite-size scaling relation. Our results suggest a similar scaling behavior to the voting distribution in the 1998 Brazilian election reported by Costa et al.Comment: 14 pages and 12 figure