We investigate the <svg style="vertical-align:-0.1638pt;width:7.3000002px;" id="M2" height="7.9499998" version="1.1" viewBox="0 0 7.3000002 7.9499998" width="7.3000002" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,7.675)"><path id="x1D45F" d="M393 379q-9 -16 -28 -29q-15 -10 -23 -2q-19 19 -36 19q-21 0 -52 -38q-57 -72 -82 -126l-40 -197q-23 -3 -75 -18l-7 7q49 196 74 335q7 43 -2 43q-7 0 -30 -14.5t-47 -37.5l-16 23q37 42 82 73t67 31q41 0 15 -113l-11 -50h4q41 71 85 117t77 46q29 0 45 -26&#xA;q13 -21 0 -43z" /></g></svg>-process nucleosynthesis during the magnetohydrodynamical (MHD) explosion of a supernova in a helium star of 3.3 <svg style="vertical-align:-3.46715pt;width:25.0875px;" id="M3" height="15.4875" version="1.1" viewBox="0 0 25.0875 15.4875" width="25.0875" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.112)"><path id="x1D440" d="M998 650l-8 -28q-71 -4 -86 -16t-22 -69l-50 -397q-3 -28 -4.5 -44t2 -29t6.5 -18.5t17 -10.5t24.5 -6.5t37.5 -3.5l-8 -28h-271l7 28q63 6 78 22t25 90l60 415h-2l-353 -552h-23l-130 536h-2l-70 -254q-44 -158 -47 -188q-5 -38 9 -51t71 -18l-6 -28h-241l8 28&#xA;q45 4 67 18.5t35 45.5q16 38 74 233l52 173q24 79 11.5 98t-89.5 26l6 28h177l136 -508l337 508h172z" /></g><g transform="matrix(.012,-0,0,-.012,17.412,15.187)"><path id="x2299" d="M573 255q0 -114 -81.5 -194.5t-197.5 -80.5t-197.5 80.5t-81.5 194.5t81.5 194.5t197.5 80.5t197.5 -80.5t81.5 -194.5zM521 255q0 96 -66.5 163.5t-160.5 67.5t-160.5 -67.5t-66.5 -163.5t66.5 -163.5t160.5 -67.5t160.5 67.5t66.5 163.5zM350 255q0 -26 -16 -42&#xA;t-40 -16t-40 16t-16 42q0 25 16 41.5t40 16.5t40 -16.5t16 -41.5z" /></g></svg>, where effects of neutrinos are taken into account using the leakage scheme in the two-dimensional (2D) hydrodynamic code. Jet-like explosion due to the combined effects of differential rotation and magnetic field is able to erode the lower electron fraction matter from the inner layers. We find that the ejected material of low electron fraction responsible for the <svg style="vertical-align:-0.1638pt;width:7.3000002px;" id="M4" height="7.9499998" version="1.1" viewBox="0 0 7.3000002 7.9499998" width="7.3000002" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,7.675)"><use xlink:href="#x1D45F" /></g></svg>-process comes out from just outside the neutrino sphere deep inside the Fe-core. It is found that heavy element nucleosynthesis depends on the initial conditions of rotational and magnetic fields. In particular, the third peak of the distribution is significantly overproduced relative to the solar system abundances, which would indicate a possible <svg style="vertical-align:-0.1638pt;width:7.3000002px;" id="M5" height="7.9499998" version="1.1" viewBox="0 0 7.3000002 7.9499998" width="7.3000002" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,7.675)"><use xlink:href="#x1D45F" /></g></svg>-process site owing to MHD jets in supernovae.

Motoaki Saruwatari

Masa-aki Hashimoto

Ryohei Fukuda

Shin-ichiro Fujimoto

<svg style="vertical-align:-0.1092pt" height="11.3125" version="1.1" viewBox="0 0 11.075 11.3125" width="11.075" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.113)"><path id="x1D445" d="M627 18l-10 -26q-79 6 -116 27t-69 76q-41 71 -71 138q-13 29 -27.5 39t-42.5 10h-46l-27 -145q-13 -74 -2.5 -88.5t78.5 -20.5l-6 -28h-271l5 28q66 6 82.5 21.5t30.5 87.5l71 387q12 66 2 78.5t-77 19.5l8 28h233q102 0 147 -29q65 -43 65 -129q0 -69 -45.5 -117&#xA;t-115.5 -72q40 -86 66 -133q39 -68 65 -101q28 -37 73 -51zM491 483q0 67 -33.5 101t-91.5 34q-35 0 -51 -10q-13 -8 -20 -48l-45 -245h49q71 0 113 28q79 52 79 140z" /></g></svg>-Process Nucleosynthesis in MHD Jet Explosions of Core-Collapse Supernovae

This paper investigates the motion of a test particle around the equilibrium points under the setup of the Robe&#x2019;s circular restricted three-body problem in which the masses of the three bodies vary arbitrarily with time at the same rate. The first primary is assumed to be a fluid in the shape of a sphere whose density also varies with time. The nonautonomous equations are derived and transformed to the autonomized form. Two collinear equilibrium points exist, with one positioned at the center of the fluid while the other exists for the mass ratio and density parameter provided the density parameter assumes value greater than one. Further, circular equilibrium points exist and pairs of out-of-plane equilibrium points forming triangles with the centers of the primaries are found. The out-of-plane points depend on the arbitrary constant <svg     style="vertical-align:-0.1638pt;width:8.7375002px;" id="M1" height="7.9499998" version="1.1" viewBox="0 0 8.7375002 7.9499998" width="8.7375002"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,7.675)"><path id="x1D705" d="M484 406q0 -21 -22 -38q-10 -7 -18 -1q-15 11 -30 11q-30 0 -77.5 -37t-74.5 -67l79 -168q11 -23 19.5 -34.5t13 -14t10.5 -2.5q9 0 30 17.5t40 42.5l17 -23q-31 -45 -57.5 -69.5t-40.5 -29.5t-31 -5q-18 0 -32 13.5t-35 55.5q-34 71 -69 160q-36 -32 -59 -56&#xA;q-12 -27 -36 -158q-44 -7 -77 -15l-5 7l82 349q6 25 -2 25q-16 0 -72 -41l-14 22q44 41 89 69.5t66 28.5q19 0 19 -32q0 -16 -6 -43l-35 -160l146 143q94 92 136 92q20 0 33 -12t13 -30z" /></g>

		
	
</svg>, of the motion of the primaries, density ratio, and mass parameter. The linear stability of the equilibrium points is studied and it is seen that the circular and out-of-plane equilibrium points are unstable while the collinear equilibrium points are stable under some conditions. A numerical example regarding out-of-plane points is given in the case of the Earth, Moon, and submarine system. This study may be useful in the investigations of dynamic problem of the &#x201c;ocean planets&#x201d; Kepler-62e and Kepler-62f orbiting the star Kepler-62.

Jagadish Singh

Oni Leke

On Robe's Circular Restricted Problem of Three Variable Mass Bodies

It has been shown earlier that Noether symmetry does not admit a form of <svg     style="vertical-align:-2.3205pt;width:33.412498px;" id="M1" height="15.0875" version="1.1" viewBox="0 0 33.412498 15.0875" width="33.412498"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,12.138)"><path id="x1D439" d="M599 650l-18 -160l-30 -2q-2 70 -11 94q-5 16 -26 24t-75 8h-94q-27 0 -33.5 -6.5t-12.5 -32.5l-43 -226h108q52 0 72.5 5t31 18t28.5 52h28l-40 -200h-28q-1 42 -6 56.5t-24.5 21t-70.5 6.5h-108l-32 -177q-13 -65 1 -80.5t88 -22.5l-8 -28h-279l6 28q61 5 77.5 20.5&#xA;t29.5 81.5l72 387l7.5 40.5t1 26.5t-4 18t-15.5 10t-24 6t-37 4l8 28h461z" /></g><g transform="matrix(.017,-0,0,-.017,10.636,12.138)"><path id="x28" d="M300 -147l-18 -23q-106 71 -159 185.5t-53 254.5v1q0 139 53 252.5t159 186.5l18 -24q-74 -62 -115.5 -173.5t-41.5 -242.5q0 -130 41.5 -242.5t115.5 -174.5z" /></g><g transform="matrix(.017,-0,0,-.017,16.517,12.138)"><path id="x1D445" d="M627 18l-10 -26q-79 6 -116 27t-69 76q-41 71 -71 138q-13 29 -27.5 39t-42.5 10h-46l-27 -145q-13 -74 -2.5 -88.5t78.5 -20.5l-6 -28h-271l5 28q66 6 82.5 21.5t30.5 87.5l71 387q12 66 2 78.5t-77 19.5l8 28h233q102 0 147 -29q65 -43 65 -129q0 -69 -45.5 -117&#xA;t-115.5 -72q40 -86 66 -133q39 -68 65 -101q28 -37 73 -51zM491 483q0 67 -33.5 101t-91.5 34q-35 0 -51 -10q-13 -8 -20 -48l-45 -245h49q71 0 113 28q79 52 79 140z" /></g><g transform="matrix(.017,-0,0,-.017,27.464,12.138)"><path id="x29" d="M275 270q0 -296 -211 -440l-19 23q75 62 116.5 174t41.5 243t-42 243t-116 173l19 24q211 -144 211 -440z" /></g>

		
	
</svg> corresponding to an action in which <svg     style="vertical-align:-2.3205pt;width:33.412498px;" id="M2" height="15.0875" version="1.1" viewBox="0 0 33.412498 15.0875" width="33.412498"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,12.138)"><use xlink:href="#x1D439"/></g><g transform="matrix(.017,-0,0,-.017,10.636,12.138)"><use xlink:href="#x28"/></g><g transform="matrix(.017,-0,0,-.017,16.517,12.138)"><use xlink:href="#x1D445"/></g><g transform="matrix(.017,-0,0,-.017,27.464,12.138)"><use xlink:href="#x29"/></g>

		
	
</svg> is coupled to scalar-tensor theory of gravity or even for pure <svg     style="vertical-align:-2.3205pt;width:33.412498px;" id="M3" height="15.0875" version="1.1" viewBox="0 0 33.412498 15.0875" width="33.412498"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,12.138)"><use xlink:href="#x1D439"/></g><g transform="matrix(.017,-0,0,-.017,10.636,12.138)"><use xlink:href="#x28"/></g><g transform="matrix(.017,-0,0,-.017,16.517,12.138)"><use xlink:href="#x1D445"/></g><g transform="matrix(.017,-0,0,-.017,27.464,12.138)"><use xlink:href="#x29"/></g>

		
	
</svg> theory of gravity taking anisotropic model into account. Here, we prove that <svg     style="vertical-align:-2.3205pt;width:33.412498px;" id="M4" height="15.0875" version="1.1" viewBox="0 0 33.412498 15.0875" width="33.412498"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,12.138)"><use xlink:href="#x1D439"/></g><g transform="matrix(.017,-0,0,-.017,10.636,12.138)"><use xlink:href="#x28"/></g><g transform="matrix(.017,-0,0,-.017,16.517,12.138)"><use xlink:href="#x1D445"/></g><g transform="matrix(.017,-0,0,-.017,27.464,12.138)"><use xlink:href="#x29"/></g>

		
	
</svg> theory of gravity does not admit Noether symmetry even if it is coupled to tachyonic field and considering a gauge in addition. To handle such a theory, a general conserved current has been constructed under a condition which decouples higher-order curvature part from the field part. This condition, in principle, solves for the scale-factor independently. Thus, cosmological evolution remains independent of the form of the chosen field, whether it is a scalar or a tachyon.

Nayem Sk

Abhik Kumar Sanyal

Field Independent Cosmic Evolution

New classes of exact solutions to the Einstein-Maxwell system is found in closed form by assuming that the hypersurface <svg     style="vertical-align:-0.1638pt;width:83.074997px;" id="M1" height="10.3875" version="1.1" viewBox="0 0 83.074997 10.3875" width="83.074997"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,10.125)"><path id="x1D461" d="M324 430l-26 -36l-112 -4l-55 -265q-13 -66 7 -66q13 0 44.5 20t50.5 40l17 -24q-38 -40 -85.5 -73.5t-87.5 -33.5q-50 0 -21 138l55 262h-80l-2 8l25 34h66l25 99l78 63l10 -9l-37 -153h128z" /></g><g transform="matrix(.017,-0,0,-.017,10.568,10.125)"><path id="x3D" d="M535 323h-483v50h483v-50zM535 138h-483v50h483v-50z" /></g><g transform="matrix(.017,-0,0,-.017,25.272,10.125)"><path id="x63" d="M390 111l17 -21q-34 -45 -80 -73.5t-89 -28.5q-91 0 -146 62t-55 147q0 118 101 195q74 57 149 57h1q59 0 90 -27q16 -14 16 -30q0 -15 -12 -29t-21 -14q-8 0 -19 11q-44 41 -101 41q-52 0 -87.5 -42.5t-35.5 -117.5q0 -49 15 -87t39 -58t49 -30t48 -10q33 0 60.5 12&#xA;t60.5 43z" /></g><g transform="matrix(.017,-0,0,-.017,32.462,10.125)"><path id="x6F" d="M257 449q92 0 154 -65t62 -158q0 -112 -67 -175t-150 -63q-98 0 -158.5 66.5t-60.5 154.5q0 59 21 106.5t54.5 75.5t71 43t73.5 15zM244 416q-48 0 -81 -47t-33 -128q0 -96 38 -158t99 -62q51 0 82 43.5t31 139.5q0 91 -36 151.5t-100 60.5z" /></g><g transform="matrix(.017,-0,0,-.017,40.944,10.125)"><path id="x6E" d="M524 0h-209v26q44 5 55 18t11 65v167q0 114 -91 114q-50 0 -109 -51v-235q0 -50 10 -61.5t55 -16.5v-26h-217v26q51 5 62 17t11 61v206q0 47 -9.5 58.5t-50.5 19.5v23q82 15 139 40v-79l67 47q47 30 83 30q60 0 94.5 -40t34.5 -112v-193q0 -50 10 -61.5t54 -16.5v-26z&#xA;" /></g><g transform="matrix(.017,-0,0,-.017,50.107,10.125)"><path id="x73" d="M319 325l-25 -7q-33 99 -103 99q-29 0 -47 -19.5t-18 -49.5t22 -49.5t62 -36.5q63 -26 95 -57t32 -79q0 -64 -50 -101t-115 -37q-35 0 -67.5 10.5t-46.5 23.5q-5 11 -11 51t-6 67l27 5q14 -53 46.5 -88.5t75.5 -35.5q29 0 50 19.5t21 50.5t-19.5 51.5t-59.5 39.5&#xA;q-28 12 -46 22.5t-38.5 27t-30.5 38.5t-10 49q0 54 42.5 92t109.5 38q48 0 88 -18q6 -15 13 -50.5t9 -55.5z" /></g><g transform="matrix(.017,-0,0,-.017,56.26,10.125)"><path id="x74" d="M298 36l-68 -35q-25 -13 -42 -13q-98 0 -98 119v290h-69l-4 11l28 29h45v72l65 67l14 -2v-137h113q8 -8 6 -21t-12 -19h-107v-256q0 -96 59 -96q29 0 61 17z" /></g><g transform="matrix(.017,-0,0,-.017,61.53,10.125)"><path id="x61" d="M433 39l-85 -51q-27 0 -47 20q-16 16 -24 44q-5 -3 -24 -16.5t-27 -18.5t-23 -13.5t-25 -12t-19 -3.5q-52 0 -86 36.5t-34 85.5q0 71 81 99q128 43 155 65v17q0 54 -23 83.5t-62 29.5q-28 0 -45 -19t-29 -66q-7 -23 -29 -23q-15 0 -29 13t-14 30t31 40q25 19 68.5 40.5&#xA;t81.5 29.5q49 0 82 -27q45 -39 45 -123v-185q0 -60 35 -60q18 0 36 11zM275 84v156q-12 -6 -49 -23t-41 -19q-31 -14 -46 -31t-15 -43q0 -35 22.5 -55.5t48.5 -20.5q19 0 42 10.5t38 25.5z" /></g><g transform="matrix(.017,-0,0,-.017,68.856,10.125)"><use xlink:href="#x6E"/></g><g transform="matrix(.017,-0,0,-.017,77.832,10.125)"><use xlink:href="#x74"/></g>

		
	
</svg> is spheroidal. This is achieved by choosing a particular form for the electric field intensity. A class of solution is found for all positive spheroidal parameter <svg     style="vertical-align:-0.0pt;width:13.3125px;" id="M2" height="11.175" version="1.1" viewBox="0 0 13.3125 11.175" width="13.3125"  xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg">
	
		
			<g transform="matrix(.017,-0,0,-.017,.062,11.113)"><path id="x1D43E" d="M764 650l-7 -26q-61 -10 -91.5 -22.5t-76.5 -48.5l-235 -184q104 -152 208 -276q31 -37 54.5 -48.5t68.5 -16.5l-7 -28h-156q-138 170 -213 284q-19 29 -33.5 35t-33.5 -7l-29 -173q-15 -75 -5.5 -90.5t74.5 -20.5l-5 -28h-260l7 28q58 5 74 21.5t30 89.5l70 378&#xA;q12 68 2 83t-72 22l6 28h257l-7 -28q-62 -7 -76 -21.5t-27 -83.5l-32 -172q29 11 78 46q112 84 217 179q18 16 23.5 25.5t-1 14.5t-26.5 8l-30 4l5 28h249z" /></g>

		
	
</svg> for a specific form of electric field intensity. In general, the condition of pressure isotropy reduces to a difference equation with variable, rational coefficients that can be solved. Consequently, an explicit solution in series form is found. By placing restrictions on the parameters, it is shown that the series terminates and there exist two classes of solutions in terms of elementary functions. These solutions contain the models found previously in the limit of vanishing charge. Solutions found are directly relating the spheroidal parameter and electric field intensity. Masses obtained are consistent with the previously reported experimental and theoretical studies describing strange stars. A physical analysis indicates that these models may be used to describe a charged sphere.

S. Thirukkanesh

New Classes of Charged Spheroidal Models

We investigate the observational constraints on the inhomogeneous big-bang nucleosynthesis that Matsuura et al. (2005) suggested that states the possibility of the heavy element production beyond <sup>7</sup>Li in the early universe. From the observational constraints on light elements of <sup>4</sup>He and D, possible regions are found on the plane of the volume fraction of the high-density region against the ratio between high- and low-density regions. In these allowed regions, we have confirmed that the heavy elements beyond Ni can be produced appreciably, where <i>p</i>- and/or <i>r</i>-process elements are produced well simultaneously.

Riou Nakamura

Katsuhiko Sato

Constraint on Heavy Element Production in Inhomogeneous Big-Bang Nucleosynthesis from the  Light Element Observations

We have analyzed the total solar irradiance (TSI) and the spectral solar irradiance as ultraviolet emission (UV) in the wavelength range 115&#x2013;180&#x2009;nm, observed with the instruments TIM and SOLSTICE within the framework of SORCE (the solar radiation and climate experiment) during the long solar minimum between the 23rd and 24th cycles. The wavelet analysis reveals an increase in the magnetic flux in the latitudinal zone of the sunspot activity, accompanied with an increase in the TSI and UV on the surface rotation timescales of solar activity complexes. In-phase coherent structures between the midlatitude magnetic flux and TSI/UV appear when the long-lived complexes of the solar activity are present. These complexes, which are related to long-lived sources of magnetic fields under the photosphere, are maintained by magnetic fluxes reappearing in the same longitudinal regions. During the deep solar minimum (the period of the absence of sunspots), a coherent structure has been found, in which the phase between the integrated midlatitude magnetic flux is ahead of the total solar irradiance on the timescales of the surface rotation.

E. E. Benevolenskaya

I. G. Kostuchenko

The Total Solar Irradiance, UV Emission and Magnetic Flux during the Last Solar Cycle Minimum

We have, in this paper, studied the stability of the ion-acoustic wave in a plasma composed of hydrogen, positively and negatively charged oxygen ions, and electrons, which approximates very well the plasma environment around a comet. Modelling each cometary component (<svg style="vertical-align:-0.0pt;width:20.75px;" id="M1" height="14.1125" version="1.1" viewBox="0 0 20.75 14.1125" width="20.75" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,14.05)"><path id="x48" d="M729 650v-28q-62 -5 -76 -19.5t-14 -75.5v-404q0 -62 13.5 -76t75.5 -19v-28h-268v28q65 5 79.5 19t14.5 76v199h-341v-199q0 -62 14 -76t76 -19v-28h-263v28q61 5 74.5 19t13.5 76v404q0 62 -14 76t-76 19v28h259v-28q-58 -5 -71 -19t-13 -76v-162h341v162&#xA;q0 61 -13.5 75.5t-72.5 19.5v28h261z" /></g><g transform="matrix(.012,-0,0,-.012,13.087,5.887)"><path id="x2B" d="M535 230h-212v-233h-58v233h-213v50h213v210h58v-210h212v-50z" /></g></svg>, <svg style="vertical-align:-0.20473pt;width:20.424999px;" id="M2" height="14.375" version="1.1" viewBox="0 0 20.424999 14.375" width="20.424999" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,14.05)"><path id="x4F" d="M381 665q131 0 226.5 -93t95.5 -239q0 -158 -96 -253t-238 -95q-137 0 -231 95t-94 238q0 142 92.5 244.5t244.5 102.5zM359 629q-89 0 -151 -74.5t-62 -208.5q0 -141 69 -233t175 -92q90 0 150.5 74t60.5 211q0 152 -69 237.5t-173 85.5z" /></g><g transform="matrix(.012,-0,0,-.012,12.763,5.887)"><use xlink:href="#x2B" /></g></svg>, and <svg style="vertical-align:-0.20473pt;width:20.424999px;" id="M3" height="11.875" version="1.1" viewBox="0 0 20.424999 11.875" width="20.424999" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.55)"><use xlink:href="#x4F" /></g><g transform="matrix(.012,-0,0,-.012,12.763,3.4)"><path id="x2212" d="M535 230h-483v50h483v-50z" /></g></svg>) by a ring distribution, we find that ion-acoustic waves can be generated at frequencies comparable to the hydrogen ion plasma frequency. The dispersion relation has been solved both analytically and numerically. We find that the ratio of the ring speed (<svg style="vertical-align:-3.3907pt;width:22.3375px;" id="M4" height="11.9625" version="1.1" viewBox="0 0 22.3375 11.9625" width="22.3375" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,7.675)"><path id="x1D462" d="M515 96q-37 -44 -84.5 -76t-71.5 -32q-12 0 -18 7t-6 34t10 75l19 89h-2q-87 -113 -181 -176q-43 -29 -83 -29q-46 0 -46 63q0 31 9 67l52 222q7 36 -1 36q-10 0 -76 -50l-13 24q47 45 92 71.5t67 26.5q18 0 21 -16.5t-8 -65.5l-56 -242q-16 -67 13 -67q41 0 114 74&#xA;t114 146l32 145l74 26h11q-52 -199 -80 -347q-8 -39 6 -39q7 0 32 17.5t47 39.5z" /></g><g transform="matrix(.012,-0,0,-.012,9.213,11.762)"><path id="x27C2" d="M619 0h-566v50h254v498h58v-498h254v-50z" /></g><g transform="matrix(.012,-0,0,-.012,17.197,11.762)"><path id="x1D460" d="M352 391q0 -31 -27 -44q-14 -7 -24 6q-39 48 -84 48q-23 0 -39.5 -15t-16.5 -40q0 -43 73 -90q49 -32 70 -58t21 -57q0 -58 -62 -105.5t-129 -47.5q-40 0 -75.5 25t-35.5 52q0 28 32 46q7 4 15 3t11 -6q19 -31 48.5 -50.5t54.5 -19.5q34 0 54 19.5t20 42.5q0 43 -65 81&#xA;q-97 56 -97 123q0 50 51 96q19 17 58 32.5t62 15.5q37 0 61 -18t24 -39z" /></g></svg>) to the thermal spread (<svg style="vertical-align:-0.1638pt;width:7.4875002px;" id="M5" height="7.9124999" version="1.1" viewBox="0 0 7.4875002 7.9124999" width="7.4875002" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,7.638)"><path id="x1D463" d="M457 332q0 -81 -41 -161.5t-105.5 -131.5t-129.5 -51q-46 0 -79 30.5t-33 86.5q0 18 7 51q18 95 46 187q6 19 6 33q0 7 -7 7q-24 0 -78 -64l-20 23q32 48 73 77t78 29q33 0 33 -46q0 -38 -10 -70q-28 -92 -39 -152q-7 -38 -7 -57q0 -78 69 -78q68 0 118 75.5t50 194.5&#xA;q0 43 -12 57q-11 12 -11 24q0 19 15 35.5t34 16.5q18 0 30.5 -34.5t12.5 -81.5z" /></g></svg><sub>ts</sub>) modifies the dispersion characteristics of the ion-acoustic wave. The contrasting behaviour of the phase velocity of the ion-acoustic wave in the presence of <svg style="vertical-align:-0.20473pt;width:20.424999px;" id="M6" height="11.875" version="1.1" viewBox="0 0 20.424999 11.875" width="20.424999" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,11.55)"><use xlink:href="#x4F" /></g><g transform="matrix(.012,-0,0,-.012,12.763,3.4)"><use xlink:href="#x2212" /></g></svg> ions for <svg style="vertical-align:-3.3907pt;width:49.125px;" id="M7" height="13.0875" version="1.1" viewBox="0 0 49.125 13.0875" width="49.125" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,8.8)"><use xlink:href="#x1D462" /></g><g transform="matrix(.012,-0,0,-.012,9.213,12.875)"><use xlink:href="#x27C2" /></g><g transform="matrix(.012,-0,0,-.012,17.197,12.875)"><use xlink:href="#x1D460" /></g><g transform="matrix(.017,-0,0,-.017,27,8.8)"><path id="x3E" d="M512 230l-437 -233v58l378 199v2l-378 200v58l437 -233v-51z" /></g><g transform="matrix(.017,-0,0,-.017,41.687,8.8)"><use xlink:href="#x1D463" /></g></svg><sub>ts</sub> (and vice versa) can be used to detect the presence of negatively charged oxygen ions and also their thermalization.

Noble P. Abraham

Sijo Sebastian

G. Sreekala

R. Jayapal

C. P. Anilkumar

Venugopal Chandu

Ion-Acoustic Instabilities in a Multi-Ion Plasma

We assume the space-time foam picture in which the vacuum is filled with a gas of virtual wormholes. It is shown that virtual wormholes form a finite (of the Planckian order) value of the energy
density of zero-point fluctuations. However such a huge value is compensated by the contribution
of virtual wormholes to the mean curvature and the observed value of the cosmological constant is
close to zero. A nonvanishing value appears due to the polarization of vacuum in external classical
fields. In the early Universe some virtual wormholes may form actual ones. We show that in the
case of actual wormholes vacuum polarization effects are negligible while their contribution to the
mean curvature is apt to form the observed dark energy phenomenon. Using the contribution of
wormholes to dark matter and dark energy we find estimates for characteristic parameters of the
gas of wormholes.

A. A. Kirillov

E. P. Savelova

Dark Energy from the Gas of Wormholes

About this journal

Journal profile

Meet the editorial board

Editor spotlight

Find out more

This journal's articles appear in a wide range of abstracting and indexing databases, and are covered by numerous other services that aid discovery and access. Find out more about where and how the content of this journal is available.

Journal of Astrophysics