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SUMMARY:Charge density oscillations around the DNA double helix
DTSTART;VALUE=DATE-TIME:20260922T140000Z
DTEND;VALUE=DATE-TIME:20260922T140500Z
DTSTAMP;VALUE=DATE-TIME:20260914T013429Z
UID:indico-contribution-536@indico.bitp.kiev.ua
DESCRIPTION:Speakers: Oleksandr Cherniak (Bogolyubov Institute for Theoret
 ical Physics)\nThe DNA macromolecule has nanometer dimensions\, a double h
 elix structure consisting of chemically bonded atoms\, and a large negativ
 e charge. Being in an aqueous environment or inside cells\, the DNA macrom
 olecule interacts mainly through electrostatic forces\, hydrogen bonds\, h
 ydration and biochemical bonding\, including medium ions\, so the environm
 ent strongly influences DNA conformation\, stability and biological functi
 ons. Positively charged ions\, named counterions\, in the aqueous medium a
 round the DNA macromolecule\, play an important role as a screening cloud.
  Their motion is typically considered as strongly damped\, in particular d
 ue to medium viscosity and collisions\, and therefore\, counterion distrib
 ution is usually calculated in the electrostatic approximation. However\, 
 some studies demonstrate the possibility of high translational mobility of
  counterions in the screening cloud and their high-frequency movements ins
 ide the hydrated shells. Thus\, a counterion evolution around the DNA doub
 le helix remains an important problem.\nWe considered kinetic equations in
  the collisionless approximation and the DNA macromolecule approximation a
 s a charged cylinder with a weak and moderate electric field to describe t
 he counterion distribution evolution in the electric field of the DNA macr
 omolecule. Using such approximations\, the dispersion equations for counte
 rion oscillatory dynamics with an infinite number of oscillatory branches 
 are obtained. It is demonstrated that each of such branches is purely real
  if it is far from other branches\, while the intersection with other bran
 ches leads to instability. The upper bound of the instability coefficient 
 of the mode\, which appears at the branch intersection point\, is estimate
 d.\n\nThe author thanks to COSY COST Action CA21101\; National Research Fo
 undation of Ukraine (project № 2025.07/0355).\n\nhttps://indico.bitp.kie
 v.ua/event/18/contributions/536/
LOCATION:Bogolyubov Institute for Theoretical Physics Conference Hall
URL:https://indico.bitp.kiev.ua/event/18/contributions/536/
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