原始密度の変動を抽出する
1E. Gawiser is at the Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA. E-mail: gawiser@astron. berkeley.edu. J. Silk is at the Departments of Physics and Astronomy and the Center for Particle Astrophysics, Univ.
Science (New York, N.Y.)
|June 5, 1998
まとめ
宇宙マイクロ波の背景放射と銀河の分布データは,一般的な宇宙学モデルに挑戦しています. しかし,冷たい + 熱いダークマターモデルは観測と一致しており,大規模なニュートリノが重要な宇宙物質を構成する可能性があることを示唆しています.
科学分野:
- コスモロジー・コスモロジーとは
- 天体物理学 天体物理学
- 素粒子物理学 素粒子物理学について
背景:
- 宇宙の進化は,原始的な密度の変動によって形成されています.
- 宇宙マイクロ波背景 (CMB) 放射線と大規模な銀河分布は,重要な観測データを提供しています.
- 宇宙の構成を理解するには,正確な宇宙学的モデルが必要です.
研究 の 目的:
- 観測データと既存の宇宙学モデルとの一致性を調査する.
- 広範囲の空間スケールにおける原始密度の変動を調査する.
- 大量のニュートリノが宇宙の物質含有量に与える潜在的貢献を決定する.
主な方法:
- 宇宙マイクロ波背景放射のアニソトロピーのデータを分析する.
- 銀河の大規模分布の観測を用いて.
- 冷たい + 熱い暗黒物質モデルを含む様々な宇宙学的モデルからの予測と観測データを比較する.
主要な成果:
- 統合されたデータは,広く受け入れられているいくつかの宇宙学モデルと矛盾しています.
- 寒い + 熱いダークマターモデルは,観測データと一致しています.
- この発見は,巨大なニュートリノが宇宙の物質の相当な部分を表す可能性があることを示唆している.
結論:
- 標準的な宇宙学モデルには,改訂が必要になるかもしれない.
- 冷たい + 熱いダークマターモデルは,宇宙構造の形成を理解するための実行可能な枠組みを提供します.
- 大量のニュートリノの存在は,宇宙の物質密度の重要な構成要素として支持されています.
関連する概念動画
01:14Extraction: Partition and Distribution Coefficients
The distribution law or Nernst's distribution law is the law that governs the distribution of a solute between two immiscible solvents. This law, also known as the partition law, states that if a solute is added to the mixture of two immiscible solvents at a constant temperature, the solute is distributed between the two solvents in such a way that the ratio of solute concentrations in the solvents remains constant at equilibrium.
For extracting a solute from an aqueous phase into an organic...
For extracting a solute from an aqueous phase into an organic...
00:56Density
Density is an important characteristic of substances, crucial in determining whether an object sinks or floats in a fluid. Its SI unit is kg/m3, and its cgs unit is g/cm3. The density of an object helps in identifying its composition, and also reveals information about the phase of the matter and its substructure. The densities of liquids and solids are roughly comparable, consistent with the fact that their atoms are in close contact. However, gases have much lower densities than liquids and...
01:05Density and Archimedes' Principle
When a lump of clay is dropped into water, it sinks. But if the same lump of clay is molded into the shape of a boat, it starts to float. Because of its shape, the clay boat displaces more water than the lump and experiences a greater buoyant force, even though its mass is the same. The same holds true for steel ships. The average density of an object majorly determines if the object will float. If an object's average density is less than that of the surrounding fluid, it will float. The reason...
01:21Current Density
The total amount of current flowing through one unit value of a cross-sectional area is referred to as current density. If the current flow is uniform, the amount of current flowing through a conductor is the same at all points along the conductor, even if the conductor area varies. The current density consists of the local magnitude and direction of the charge flow, which varies from point to point. Current density is measured in amperes per meter square, and direction is defined as the net...
01:17The Principle of Superposition and the Gravitational Field
The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a point object is the vector sum of the gravitational forces on it due to various objects. The principle helps calculate the force by listing the individual forces and then vectorially summing them up. However, it should be noted that the principle of superposition is not always apparent. In the presence of a second force, the first force could...
01:27Density, Specific Weight, Specific Gravity and Compressibility of Fluid
Density, specific weight, specific gravity, and compressibility are fundamental properties of fluids. Density is the mass per unit volume, characterizing the mass of a fluid system. It influences buoyancy, pressure, flow dynamics, viscosity, thermal conductivity, and sound propagation. For instance, in pipeline design, accurate density measurements ensure that the pipeline can handle the fluid's mass.
Specific weight represents the weight per unit volume and is calculated by multiplying density...
Specific weight represents the weight per unit volume and is calculated by multiplying density...