Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Utilizing Monte Carlo Methods and Shifting to Preserve Causality in Particle Simulations

Singh Chauhan, Aryan LU (2026) FYTK02 20242
Particle and nuclear physics
Department of Physics
Abstract
This thesis investigates the use of parton shifting technique facilitated by Monte Carlo methods to preserve causality in relativistic particle simulations, focusing on parton cascade models used in high-energy nuclear collisions. In such simulations, relativistic effects can lead to frame-dependent collision ordering, resulting in causality violations. To address this issue, a parton shifting method is implemented in which colliding partons are relocated to a common interaction point in their center-of-momentum frame. This ensures that collision sequences remain consistent across different reference frames. The results demonstrate that parton shifting successfully removes frame-dependent inconsistencies and preserves causal ordering,... (More)
This thesis investigates the use of parton shifting technique facilitated by Monte Carlo methods to preserve causality in relativistic particle simulations, focusing on parton cascade models used in high-energy nuclear collisions. In such simulations, relativistic effects can lead to frame-dependent collision ordering, resulting in causality violations. To address this issue, a parton shifting method is implemented in which colliding partons are relocated to a common interaction point in their center-of-momentum frame. This ensures that collision sequences remain consistent across different reference frames. The results demonstrate that parton shifting successfully removes frame-dependent inconsistencies and preserves causal ordering, improving the physical reliability of relativistic transport simulations. (Less)
Popular Abstract
When particles collide at extremely high energies the rules of Einstein's relativity become unavoidable. AT these speeds, different observers may disagree on the collision sequence. This creates a challenge for computer simulations that attempt to model how fundamental particles. In many commonly used simulation methods, particle interactions are scheduled using a single global clock. While convenient, this approach can lead to unrealistic outcomes: a particle may appear to interact with two others at the same time, or the order of collisions may change when viewed from a different reference frame. These effects violate causality- the principle that causes must always precede their effects- and can make simulation results unreliable. This... (More)
When particles collide at extremely high energies the rules of Einstein's relativity become unavoidable. AT these speeds, different observers may disagree on the collision sequence. This creates a challenge for computer simulations that attempt to model how fundamental particles. In many commonly used simulation methods, particle interactions are scheduled using a single global clock. While convenient, this approach can lead to unrealistic outcomes: a particle may appear to interact with two others at the same time, or the order of collisions may change when viewed from a different reference frame. These effects violate causality- the principle that causes must always precede their effects- and can make simulation results unreliable. This project tests a solution known as parton shifting. Instead of allowing collisions to occur at frame dependent times, colliding particles are shifted so that their interaction happens at a single, well-defined space-time point in their shared COM-frame. This guarantees that all observers agree on the causal structure of the interaction, even if they measure different times. By applying this method withing Monte Carlo particle simulation, the study shows that causality violations can be completely eliminated without sacrificing realism or efficiency. The approach improves the physical consistency of simulations, ensuring that they remain a reliable tool. (Less)
Please use this url to cite or link to this publication:
author
Singh Chauhan, Aryan LU
supervisor
organization
course
FYTK02 20242
year
type
M2 - Bachelor Degree
subject
language
English
id
9221522
date added to LUP
2026-02-04 08:50:38
date last changed
2026-02-04 08:50:38
@misc{9221522,
  abstract     = {{This thesis investigates the use of parton shifting technique facilitated by Monte Carlo methods to preserve causality in relativistic particle simulations, focusing on parton cascade models used in high-energy nuclear collisions. In such simulations, relativistic effects can lead to frame-dependent collision ordering, resulting in causality violations. To address this issue, a parton shifting method is implemented in which colliding partons are relocated to a common interaction point in their center-of-momentum frame. This ensures that collision sequences remain consistent across different reference frames. The results demonstrate that parton shifting successfully removes frame-dependent inconsistencies and preserves causal ordering, improving the physical reliability of relativistic transport simulations.}},
  author       = {{Singh Chauhan, Aryan}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Utilizing Monte Carlo Methods and Shifting to Preserve Causality in Particle Simulations}},
  year         = {{2026}},
}