Related Experiment Video
Updated: Jan 4, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
8.9K
Nonlinear Dynamics of Preheating after Multifield Inflation with Nonminimal Couplings
Rachel Nguyen1, Jorinde van de Vis2, Evangelos I Sfakianakis2,3
1Department of Physics, Kenyon College, Gambier, Ohio 43022, USA.
Physical Review Letters
|November 9, 2019
Summary
We studied multifield models with nonminimal couplings using lattice simulations. Large couplings cause rapid preheating, suppressing multifield signatures and aligning predictions with cosmic microwave background observations.
Area of Science:
- Cosmology
- Theoretical Physics
- Particle Physics
Background:
- Postinflationary dynamics in multifield models are crucial for understanding the early universe.
- Nonminimal couplings introduce nonlinear effects that require advanced simulation techniques.
- Understanding thermalization and preheating is key to connecting theory with observational data.
Purpose of the Study:
- To investigate the postinflationary dynamics of multifield models with nonminimal couplings.
- To capture nonlinear effects such as backreaction and rescattering using lattice simulations.
- To determine the impact of nonminimal couplings on preheating, thermalization timescales, and primordial observables.
Main Methods:
- Utilized lattice simulations to model multifield dynamics with nonminimal couplings.
- Measured the effective equation of state and timescales for thermalization.
- Analyzed the influence of varying nonminimal coupling constants on particle production and attractor behavior.
Main Results:
- Identified efficient particle production and nearly instantaneous preheating for large nonminimal coupling constants.
- Observed the persistence of strong single-field attractor behavior throughout preheating.
- Found that multifield signatures are suppressed, leading to predictions consistent with observations.
Conclusions:
- Nonminimal couplings significantly impact early universe dynamics, leading to rapid preheating.
- The observed suppression of multifield signatures ensures that model predictions align with cosmic microwave background anisotropy data.
- These findings refine our understanding of primordial perturbation spectra in multifield cosmological models.
Related Concept Videos
01:24Heat and Free Expansion
2.7K
The work done by a thermodynamic system depends not only on the initial and final states but also on the intermediate states—that is, on the path. Like work, when heat is added to a thermodynamic system, it undergoes a change of state, and the state attained depends on the path from the initial state to the final state. Consider an ideal gas cylinder fitted with a piston. When the cylinder is heated at a constant temperature, the gas molecules absorb energy and expand slowly in a...
2.7K
01:12Temperature Dependent Deformation
337
In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...
337
01:27¹H NMR: Long-Range Coupling
2.5K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
2.5K
01:17Non-conservative Forces
9.2K
Non-conservative forces are dissipative forces such as friction or air resistance. These forces take energy away from a system as it progresses. Unlike conservative forces, non-conservative forces do not have potential energy associated with them. This is because the energy is lost to the system and cannot be turned into useful work later.
Also unlike their conservative counterparts, they are path-dependent; where the object starts and stops does matter. For example, a grinding wheel applies a...
Also unlike their conservative counterparts, they are path-dependent; where the object starts and stops does matter. For example, a grinding wheel applies a...
9.2K
01:20Mechanisms of Heat Transfer II
4.1K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
4.1K
02:44Heating and Cooling Curves
26.4K
When a substance—isolated from its environment—is subjected to heat changes, corresponding changes in temperature and phase of the substance is observed; this is graphically represented by heating and cooling curves.
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
26.4K