| An_Exposition_on_Inflationary_Cosmology In this paper, the fundamentals of modern cosmology for an isotropic and homogeneous space-time will be reviewed. Other issues suggesting a more general theory are presented and inflation is introduce |
| Friedmann-Lemaitre_Cosmological_Models Article from Eric Weisstein's World of Physics. |
| From_Newton\'s_Laws_to_the_Wheeler-deWitt_equation This is a pedagogical paper which explains some ideas in cosmology at a level accessible to undergraduate students. Following standard quantization procedures the Wheeler-DeWitt equation |
| Introduction_to_Cosmology_-_Astrophysics These notes form an introduction to cosmology with special emphasis on large scale structure, the cmb anisotropy and inflation. In some places a basic familiarity with particle physics is assume |
| Introduction_to_Cosmology_-_High_Energy_Physics_-_Phenomenology A set of postrscript lecture notes by George Lazarides on the basic principles of cosmology. |
| Introduction_to_Inflationary_Cosmology Introduction to cosmology and inflation by Scott Watson of Brown University. |
| Introductory_review_of_cosmic_inflation These lecture notes provide an introduction to cosmic inflation. In particular the basic concepts of inflation, generation of density perturbations, and reheating after inflation. |
| Knowing_the_Universe_and_Its_Secrets Learn about the life and energy processes of stars and galaxies. Page has explanations of ancient and modern theories, as well as charts and astronomical photos. |
| Low_Density_Inflationary_Universes A review of the geometry and density of the universe, with a focus on inflationary models. |
| Mathematical_Cosmology A review of current unsolved problems in mathematical cosmology |
| Minkowski_Functionals_in_Cosmology Minkowski functionals provide a novel tool to characterize the large-scale galaxy distribution in the Universe. Here we give a brief tutorial on the basic features of these morphological measure |
| Multidimensional_Gravity_and_Cosmology A short review of recent results on exact solutions in multidimensional cosmology |
| New_Developments_in_Cosmology A review of how the understanding of our Universe has evolved |
| Numerical_Simulations_in_Cosmology_I__Methods This lecture gives a short introduction to different methods used in cosmology. The focus is on major features of N-body simulations: equations, main numerical techniques, effects of resolution, and m |
| Particle_Aspects_of_Cosmology_and_Baryogenesis An introduction to particle aspects of cosmology with particular reference to primordial nucleosynthesis, dark matter and baryogenesis is provided. In particular, various scenarios-GUT baryogenesis, e |
| The_Possible_Geometries_for_Space A short article on the possible structures for space in the Friedmann-Robertson-Walker model |
| A_Quantum_Leap_for_Cosmology A theory that unites quantum mechanics and general relativity claims that there was no first moment in time, but it still agrees with the predictions of classical cosmology. |
| A_Review_of_Inflationary_Cosmology The aim of this lecture is to highlight two areas of recent progress in inflationary cosmology, namely reheating and the quantum theory of cosmological perturbations. |
| Scientific_American__Four_Keys_to_Cosmology The big bang theory works better than ever. If only cosmologists could figure out that mysterious acceleration.... |
| Should_We_Believe_in_Big_Bang? Pablo G. Ostrov explains Big Bang theory for non-scientists. |
| A_Simple_Introduction_to_Pre-Big-Bang_Physics/Cosmology A simple, non-technical introduction to the pre-big bang scenario is given, emphasizing physical motivations, considerations, and consequences over formalism. |
| Space,_Time,_and_Cosmology Learn about the origins of the universe and its fate. Einstein's Theory of Relativity is both interesting and comprehensible. |
| 1st_SPOT_Cosmology References to cosmological sites featuring in-depth coverage of issues like dark matter, black holes and symmetric theory. |
| Stephen_Hawking\'s_Universe Detailed explanations of the most important ideas and developments in human understanding of the universe. Includes original essays by some of today's leading figures in cosmology, along with original |
| String_Cosmology A lecture on aspects of superstring theory and cosmology. |
| String_Cosmology__A_Review Talk presented at COSPAR '02, Houston, Texas, October 2002. |
| A_Study_of_a_Model_Cosmology Contains report of a seminar on a model cosmology with a preliminary introduction to General Relativity. |
| Topology_of_the_Universe A thesis (in PDF format) which studies the possible topologies of the universe and their physical implications. |
| University_of_Alberta_Theoretical_Physics_Institute Includes a staff list and a brief description of work done in that centre. |
| Brad_McRae Contains dissertation chapters and software for use in spatial ecology and population genetic analyses. |
| CAMASE_Project Focused on the development and testing of quantitative methods for research on agricultural systems and the environment. |
| Division_of_Landscape_Ecology_and_Planning,_University_Giessen Discusses the interactions between components, structures, processes, functions and services of biodiversity that are studied on different levels of hierarchy in biotic systems. |
| Forest_Landscape_Ecology_Lab,_University_of_Wisconsin-Madison Research lab focusing on forested ecosystems, primarily in the Great Lakes region. |
| Geospatial_Analysis_and_Modeling_of_Ecological_Systems_Laboratory,_University_of_Central_Florida Promotes the integration of geographic information systems (GIS) and remote sensing technology with ecological modeling to simulate dynamic, spatially-explicit patterns and processes at scales ranging |
| GIS_in_Species_Conservation_and_Management Short articles about current and recent projects using geographic information systems (GIS) and spatial analysis in conservation and management of species and landscapes. Projects involve habitat mode |
| Institute_of_Landscape_Ecology Multi-disciplinary research institute of the Academy of Sciencies of the Czech Republic, focused on basic and applied researches of the landscape and its biotic and abiotic components. |
| International_Society_for_Ecological_Modelling Promotes the international exchange of ideas, scientific results, and general knowledge in the area of the application of systems analysis and simulation in ecology and natural resource management. |
| JDEVS_Toolkit Simulation toolkit for ecosystem modeling. Publications and download. Contains 2D and 3D applets of ecosystems. |
| Landscape_Ecology_and_Modeling_Laboratory,_Arizona_State_University Research projects, people, publications emphasizing theoretical spatial ecology. |
| Landscape_Ecology_Group,_Utrecht_University Provides information on research topics and courses related to fundamental and applied wetland research. |
2. SPHERICAL SPACE or CLOSED SPACE: In the two dimension analogy,
this model resembles a beach ball. Again the stars and planets
are
little dots on the surface of the ball. This is also the only model
which
does not have an infinite number of stars, which makes it a very
popular
model.
3. OPEN SPACE: ( There are several technical names for this model, and
open model actually includes flat space as well) There is no two
dimensional
form of this space, but if you cut a small piece out, it would look
like
a saddle. The entire space would be created by gluing several saddles
together
and smoothing the seam.
General Relativity also changed
cosmology
by not allowing the Universe to be STATIC, the Universe must change
with
time. Furthermore, observations of far away stars shows the
Universe
is expanding. Using the equations of general relativity, it can be
shown
that the expansion of the Universe is slowing down, but the amount of
slowing
depends on the amount of stuff in the Universe.
1. FLAT SPACE: If the density of matter in the Universe is exactly
right
, then the Universe will be flat. In a flat Universe, space will expand
forever, but will eventually reach a constant rate of expansion.
2. CLOSED SPACE: If there is more matter in the Universe, then the
Universe
is closed. It will continue expanding for about 15 billion years, and
then
begin contracting again. ( So in about 50 billion years, everything
will
crunch together). This is also a good model for explaining the
big
bang. Imagine taking a balloon (the initial Universe) and drawing
points
uniformly on the surface ( stars and planets and such). Then begin
inflating
the balloon, (the Universe expands) and notice the points do not move
on
the surface, the space between them expands. This is what happens in
the
Universe: there is not a point from which all matter spewed forth, the
matter was uniformly distributed through space while space expanded.
3. OPEN SPACE: If there is less matter in the Universe, then the
Universe
is open. It will expand forever, and while this may seem to be a nicer
situation, more complicated calculations show that the Universe and
everything
in it will become too cold to support life.
Dark Matter
You may have heard
about
the search for dark matter in the media and science fiction. Recall
that
the cosmological model depends on the density of matter in the
Universe,
with low densities giving an infinite universe which expands forever.
Currently,
astronomers have only found about 1/50 of the amount of matter required
to produce a closed or flat universe, and so those who like these
models
are looking for more stuff. If the universe is going to contract, then
98% of the universe must not be visible. Hence it is dubbed dark
matter.
Some prospects for dark matter
are:
1. Neutrino Mass: Neutrino's are extremely small
particles
which are plentiful in the universe. So far no one has been able to
measure
the mass of the neutrino. There are so many that even a tiny mass
could give enough density to close the universe. Update: It is now known that the
neutrinos have mass, but that the known types of neutrinos are far too
light to explain dark matter.
2. Black Holes and Brown Dwarfs: These are large, high density
objects which emit no light. If there are many such objects in the
universe,
then they could contribute enough to close the universe.
Update: More precise measurements of the relative abundances of
hydrogen and helium, (and other light elements) have place severe
restrictions on the amount of ordinary matter in the Universe, and have
excluded it as dark matter. Therefore brown dwarfs are ruled out and
black holes are very unlikely as a solution to the dark matter problem.
It is also possible that the problem is in our understanding of
gravity, leading to several proposals (such as Modified Newtonian
Dynamics or the TeVeS model) in which gravity is altered to reproduce
the effects of matter.
*UPDATES*
Since this site was written some very
important discoveries have been made:
1- The Wilkinson Microwave Anisotropy Probe (WMAP) measured the
microwave radiation in space left over from the Big Bang. The results
proved that space is flat,
and that only 5% of the energy in the Universe is in known forms of
matter, while another 25% is in the form of dark matter.
2 - Supernovae measurements revealed the biggest surprise of the last
decade, the universe is not only expanding but it is accelerating. This
discovery, along with measurments by WMAP, have lead to the realization
that 70% of the energy in the Universe is not any form of matter, but
some mysterious DARK ENERGY.
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