1,126 research outputs found

    The role of impacting processes in the chemical evolution of the atmosphere of primordial Earth

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    The role of impacting processes in the chemical evolution of the atmosphere of primordial Earth is discussed. The following subject areas are covered: (1) Earth's initial atmosphere; (2) continuous degassing; (3) impact processes and the Earth's protoatmosphere; and (4) the evolution of an impact-generated atmosphere

    Early stages in the evolution of the atmosphere and climate on the Earth-group planets

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    The early evolution of the atmospheres and climate of the Earth, Mars and Venus is discussed, based on a concept of common initial conditions and main processes (besides known differences in chemical composition and outgassing rate). It is concluded that: (1) liquid water appeared on the surface of the earth in the first few hundred million years; the average surface temperature was near the melting point for about the first two eons; CO2 was the main component of the atmosphere in the first 100-500 million years; (2) much more temperate outgassing and low solar heating led to the much later appearance of liquid water on the Martian surface, only one to two billion years ago; the Martian era of rivers, relatively dense atmosphere and warm climate ended as a result of irreversible chemical bonding of CO2 by Urey equilibrium processes; (3) a great lack of water in the primordial material of Venus is proposed; liquid water never was present on the surface of the planet, and there was practically no chemical bonding of CO2; the surface temperature was over 600 K four billion years ago

    Finite type modules and Bethe Ansatz for quantum toroidal gl(1)

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    We study highest weight representations of the Borel subalgebra of the quantum toroidal gl(1) algebra with finite-dimensional weight spaces. In particular, we develop the q-character theory for such modules. We introduce and study the subcategory of `finite type' modules. By definition, a module over the Borel subalgebra is finite type if the Cartan like current \psi^+(z) has a finite number of eigenvalues, even though the module itself can be infinite dimensional. We use our results to diagonalize the transfer matrix T_{V,W}(u;p) analogous to those of the six vertex model. In our setting T_{V,W}(u;p) acts in a tensor product W of Fock spaces and V is a highest weight module over the Borel subalgebra of quantum toroidal gl(1) with finite-dimensional weight spaces. Namely we show that for a special choice of finite type modules VV the corresponding transfer matrices, Q(u;p) and T(u;p), are polynomials in u and satisfy a two-term TQ relation. We use this relation to prove the Bethe Ansatz equation for the zeroes of the eigenvalues of Q(u;p). Then we show that the eigenvalues of T_{V,W}(u;p) are given by an appropriate substitution of eigenvalues of Q(u;p) into the q-character of V.Comment: Latex 42 page

    Form factors and action of U_{\sqrt{-1}}(sl_2~) on infinite-cycles

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    Let p={Pn,l}n,l∈Zβ‰₯0nβˆ’2l=m{\bf p}=\{P_{n,l}\}_{n,l\in\Z_{\ge 0}\atop n-2l=m} be a sequence of skew-symmetric polynomials in X1,...,XlX_1,...,X_l satisfying deg⁑XjPn,l≀nβˆ’1\deg_{X_j}P_{n,l}\le n-1, whose coefficients are symmetric Laurent polynomials in z1,...,znz_1,...,z_n. We call p{\bf p} an ∞\infty-cycle if Pn+2,l+1∣Xl+1=zβˆ’1,znβˆ’1=z,zn=βˆ’z=zβˆ’nβˆ’1∏a=1l(1βˆ’Xa2z2)β‹…Pn,lP_{n+2,l+1}\bigl|_{X_{l+1}=z^{-1},z_{n-1}=z,z_n=-z} =z^{-n-1}\prod_{a=1}^l(1-X_a^2z^2)\cdot P_{n,l} holds for all n,ln,l. These objects arise in integral representations for form factors of massive integrable field theory, i.e., the SU(2)-invariant Thirring model and the sine-Gordon model. The variables Ξ±a=βˆ’log⁑Xa\alpha_a=-\log X_a are the integration variables and Ξ²j=log⁑zj\beta_j=\log z_j are the rapidity variables. To each ∞\infty-cycle there corresponds a form factor of the above models. Conjecturally all form-factors are obtained from the ∞\infty-cycles. In this paper, we define an action of Uβˆ’1(sl~2)U_{\sqrt{-1}}(\widetilde{\mathfrak{sl}}_2) on the space of ∞\infty-cycles. There are two sectors of ∞\infty-cycles depending on whether nn is even or odd. Using this action, we show that the character of the space of even (resp. odd) ∞\infty-cycles which are polynomials in z1,...,znz_1,...,z_n is equal to the level (βˆ’1)(-1) irreducible character of sl^2\hat{\mathfrak{sl}}_2 with lowest weight βˆ’Ξ›0-\Lambda_0 (resp. βˆ’Ξ›1-\Lambda_1). We also suggest a possible tensor product structure of the full space of ∞\infty-cycles.Comment: 27 pages, abstract and section 3.1 revise
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