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Igor Yu. Potemine

Publications and source records attributed to Igor Yu. Potemine.

9 recordsLinked to original sources
arXiv2024

Stellar flybies within 1 ly from the Sun and stars passing through the Hills cloud

We reexamine the SIMBAD database with incorporated Gaia DR3 parallaxes and proper motions. Appropriate query searches allow us to find several nearby stars with measured radial velocities having flybies within 1 ly from the Sun (in linear approximation). The closest past flyby $\approx 215.7$ kyr ago at $\approx 0.136$ pc is attributed to the star UCAC4 323-037188, currently located at 21.74 pc from the Sun. If the radial velocity of a star is unknown, we attribute to it an ``advantageous'' value of $\pm 50$ km/s. It allows us to create an additional list of ``Nemesis candidates'' for the perforation of the inner Oort cloud. The closest potential flyby at $\approx 0.015$ pc ($\approx$ 0.050 ly $\approx$ 3147 AU) from the Sun is attributed to GALEX J013712.5-012958 (Gaia DR3 2508809660245711360). It is currently located at the distance of about 111.1 pc and belongs to the Pisces-Eridanus stream. Also, close flybies of some massive bright stars (Algol, A-giant HD 107914, A-subgiant HD 2733 and B-subgiant HD 165704) are analyzed. Finally, we notice that B1-star BD+60 596, whose proper motions and radial velocity are both small, can be considered as the Sun's pseudo-stream companion.

astro-ph.SR↗
arXiv2022

Hyperverse, 5-dimensional gravity and multiverses as nested Gogberashvili shells

We consider the Hyperverse as a collection of multiverses in 5-dimensional spacetime with gravitational constant $G$. Each multiverse in our simplified model is a bouquet of nested spherical Gogberashvili shells. If $g_k$ is the gravitational constant of a thin shell $S_k$ and $\varepsilon_k^{}$ its thickness then $G\sim\varepsilon_k^{}g_k^{}$. The physical universe is supposed to be one of those shells inside the local nested bouquet called Local Multiverse. We relate this construction to Robinson-Trautman metrics describing expanding spacetimes with spherical gravitational waves. Supermassive astronomical black holes, located at cores of elliptic/spiral galaxies, are also conjecturally described within this theory. Our constructions are equally consistent with the modern theory of cosmological coupling.

gr-qc↗
arXiv2021

Amalgamated Geometric Structure of the Local Multiverse

We consider multiverses as time-amalgamated multiply warped products of Lorentzian (Einstein) manifolds. We define the Local Multiverse as timely-connected component of our physical (3+1)-spacetime. It is a collection of ``parallel universes" with (mutually) synchronized timelines. Metaphysical considerations suggest that the Local Multiverse could be an extremely complex agglomeration with, at least, several hundred parallel universes in the Solar neighbourhood (and many thousands in galaxy bulks). In this paper we study a simplified time-almagamated globally hyperbolic model. Our picture implies the multiversality of elementary particles which are, actually, transcosmic (super)strings with multiple endpoints on parallel universes considered as D-branes.

gr-qc↗
arXiv2020

Hecke-Langlands Duality and Witten's Gravitational Moonshine

We show that there is a dual description of conformal blocks of $d=2$ rational CFT in terms of Hecke eigenfields and eigensheaves. In particular, partition functions, conformal characters and lattice theta functions may be reconstructed from the action of Hecke operators. This method can be applied to: 1) rings of integers of Galois number fields equipped with the trace (or anti-trace) form; 2) root lattices of affine Kac-Moody algebras and WZW-models; 3) minimal models of Belavin-Polyakov-Zamolodchikov and related $d=2$ spin-chain/lattice models; 4) vertex algebras of Leech and Niemeier lattices and others. We also use the original Witten's idea to construct the 3-dimensional quantum gravity as the AdS/CFT-dual of $c=24$ Monster vertex algebra of Frenkel-Lepowsky-Meurman. Concerning the geometric Langlands duality, we use results of Beilinson-Drinfeld, Frenkel-Ben-Zvi, Gukov-Kapustin-Witten and many others (cf. references).

hep-th↗
arXiv2013

Nemesis encounters of nearby Hipparcos stars

Very close encounters of stars might lead to significant perturbations of their Oort-type clouds, planetesimal belts and planetary systems. We have calculated encounter parameters of Hipparcos stars using HIP2, Pulkovo and CRVAD2 catalogs of radial velocities. It turns out that some stars have encounters within 0.1 pc from each other and might be on an essential collision course up to few thousands AU. We present here examples with accurate astrometric data and stable with respect to errors of radial velocities within $\pm 0.3$ km/s. They include $β$ vs. $γ$ Virginis, 61 Cygni vs. $χ^1$ Orionis as well as close encounters involving $η$ Boötis, AB Doradus, 61 Ursæ Majoris and others.

astro-ph.SR↗
arXiv2010

Transit of Luyten 726-8 within 1 ly from Epsilon Eridani

This is one of results from our program of massive simulations of close encounters for all nearby stars. Epsilon Eridani is an extremely interesting star having one confirmed planet and multiple asteroid and debris belts. It should have a quite massive Oort cloud as well. Deltorn et al. searched for past Nemesis encounters of $\varepsilon$ Eri. In this paper we show that, according to current astrometric data, an other famous nearby star Luyten 726-8AB (=BL/UV Ceti) will pass at $\lesssim$ 0.93 ly from Epsilon Eridani in $\approx$ 31.5 kyr. So, it will probably pierce through the outer part of the hypothetical Oort cloud of $ε$ Eri. BL/UV Ceti has only about 20 percent of the solar mass. Nevertheless, it could influence directly some long-period comets of Epsilon Eridani. The duration of mutual transit of two star systems within 1 ly from each other is $\gtrsim$ 4.6 kyr. Our simulations show that stellar encounters within 1 ly might be more frequent than previously thought. It could explain Proxima's peculiar trajectory with respect to $α$ Cen AB or even Sedna's trajectory in the solar system.

astro-ph.SR↗
arXiv2010

Giant Nemesis candidate HD 107914 / HIP 60503 for the perforation of Oort cloud

So far, GJ 710 is the only known star supposed to pass through outskirts of the solar system within 1 ly. We have reexamined the SIMBAD database for additional stellar candidates (from highest ratios of squared parallax to total proper motion) and compared them with new HIP2 parallaxes and known radial velocities. At the moment, the best nominee is double star HD 107914 in the constellation Centaurus at $\approx$ 78.3 pc from the Sun whose principal component is a white (A-type) giant. It does not seem to appear neither in general catalogues of radial velocities available at SIMBAD nor in authoritative Garcia-Sanchez et al. papers on stellar encounters with the solar system. Awaiting for the value $v_r$ of its radial velocity, uknown to the author, we have calculated limits of $|v_r|$ necessary to this star to pass within 1 ly and 1 pc from the Sun in linear approximation. A very accurate value of its total proper motion is also extremely important. In the case of $v_r=-100$ km/s and most "advantageous" HIP2 data, HD 107914 could pass as near as 8380 AU from the Sun in an almost direct collision course with the inner part of the solar system! Inversely, if $v_r$ had a great positive value, then HIP 60503 could be the creator of peculiar trajectories of detached trans-Neptunian objects like Sedna.

astro-ph.SR↗
arXiv2001

Quantum Langlands duality and mirror symmetry

We show that (quantum) D-modules of Givental type on affine flag varieties are transformed to D-modules of Beilinson-Drinfeld type on $n$-reduced Sato Grassmannians via affine Miura transformation.

math.AG↗