5 v 1 1 4 A ug 2 00 0 Latest cosmological constraints on the densities of hot and cold dark matter

نویسنده

  • Andrew J. S. Hamilton
چکیده

As experimentalists step up their pursuit of cold dark matter particles and neutrino masses, cosmological constraints are tightening. We compute the joint constraints on 11 cosmological parameters from cosmic microwave background and large scale structure data, and find that at 95% confidence, the total (cold+hot) dark matter density is hΩdm = 0.20 +.12 −.10 with at most 38% of it being hot (due to neutrinos). A few assumptions, including negligible neutrinos, tighten this measurement to hΩdm = 0.13 +0.04 −0.02 , i.e., 2.4× 10 kg/m give or take 20%.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

ar X iv : 0 70 5 . 45 49 v 1 [ gr - q c ] 3 1 M ay 2 00 7 Quantum - theoretical description of the cosmological constant as the zero - point energy

The present paper seeks to construct a quantum theory of the cosmological constant in which its presently observed very small value emerges naturally. Large scale cosmological observations over the past decade (see references cited in [1], and [2-4]) have provided data which are in accord with the simplest cosmological model LCDM (Λ + Cold Dark Matter) [4-7]. This model is governed by the homog...

متن کامل

Cold + Hot Dark Matter after Super-kamiokande

The recent atmospheric neutrino data from Super-Kamiokande provide strong evidence of neutrino oscillations and therefore of non-zero neutrino mass. These data imply a lower limit on the hot dark matter (i.e., light neutrino) contribution to the cosmological density Ων > ∼ 0.001 — almost as much as that of all the stars in the universe — and permit higher Ων . The “standard” COBE-normalized cri...

متن کامل

X iv : h ep - p h / 03 07 06 2 v 1 4 J ul 2 00 3 Cosmological and astrophysical limits on brane fluctuations

We consider a general brane-world model parametrized by the brane tension scale f and the branon mass M . For low tension compared to the fundamental gravitational scale, we calculate the relic branon abundance and its contribution to the cosmological dark matter. We compare this result with the current observational limits on the total and hot dark matter energy densities and derive the corres...

متن کامل

ar X iv : a st ro - p h / 99 09 30 1 v 1 1 7 Se p 19 99 CMBology

The details of the CMB power spectrum are being revealed through the combined efforts of the world's CMBologists. The current data set constrains several cosmological parameters. A combination with other (non-lensing) constraints yields estimates of the cosmological constant: Ω Λ = 0.65 ± 0.13, the mass density: Ω m = 0.23 ± 0.08 and the age of the Universe: t o = 13.4 ± 1.6. Lensing data is no...

متن کامل

ar X iv : a st ro - p h / 95 04 01 4 v 1 5 A pr 1 99 5 CITA - 95 - 9 A Warm - Plus - Hot Dark Matter

We investigate a new hybrid-model universe containing two types of dark matter, one " warm " and the other " hot ". The hot component is an ordinary light neutrino with mass ∼ 25h 2 eV while the warm component is a sterile neutrino with mass ∼ 700h 2 eV. The two types of dark matter arise entirely within the neutrino sector and do not require separate physical origins. We calculate the linear t...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000