相关论文: Microwave and submillimeter molecular transitions …

We estimate sensitivity coefficients to variation of the fine-structure constant alpha and electron-to-proton mass ratio mu for microwave Lambda-type transitions in CH molecule and for inversion-rotational transitions in partly deuterated…

Many modern theories predict that the fundamental constants depend on time, position, or the local density of matter. We develop a spectroscopic method for pulsed beams of cold molecules, and use it to measure the frequencies of microwave…

Quantum mechanical tunneling inversion transition in ammonia NH3 is actively used as a sensitive tool to study possible variations of the electron-to-proton mass ratio, mu = m_e/m_p. The molecule H3O+ has the inversion barrier significantly…

Sensitivity to temporal variation of the fundamental constants may be strongly enhanced in transitions between narrow close levels of different nature. This enhancement may be realized in a large number of molecules due to cancelation…

We study the sensitivity of the microwave and submillimeter transitions of the isotopologues of hydronium to the variation of the electron-to-proton mass ratio mu. These sensitivities are enhanced for the low frequency mixed…

The search for variation of the fundamental constants such as the fine structure constant $\alpha$ ($\alpha=e^2/\hbar c$) and the ratios of fundamental masses (e.g., electron to proton mass ratio $\mu=m_e/m_p$) is reviewed. Strong emphasis…

Quasi-forbidden electronic transitions in atoms and quasi-degenerate vibronic transitions in molecules serve as powerful probes of hypothetical temporal variations of fundamental constants. Computation of the sensitivity of a transition to…

Recent observation of several microwave transitions in H2O2 from the interstellar medium [Astron. Astrophys., 531, L8 (2011)] raised interest to this molecule as yet another sensitive probe of the tentative variation of the…

We determine the sensitivity to a possible variation of the proton-to-electron mass ratio \mu for torsion-wagging-rotation transitions in the ground state of methylamine (CH3NH2). Our calculation uses an effective Hamiltonian based on a…

We present the quantum-mechanical calculations of the dimensionless sensitivity coefficients Q to small changes in the fundamental physical constant mu = m_e/m_p - the electron-to-proton mass ratio - for a number of low-frequency (1-50 GHz)…

We estimate sensitivity coefficients Q_\mu to variation of the electron-to-proton mass ratio \mu for microwave transitions in partly deuterated ammonia NH2D and ND2H. Because of the mixing between rotational and inversion degrees of freedom…

We report on the using of torsion-rotational transitions in the CH3OH and (13)CH3OH molecules to evaluate possible variations of the physical constant mu=m_e/m_p - the electron-to-proton mass ratio - from spectral observations of emission…

Spatial and temporal variations in the electron-to-proton mass ratio, mu, and in the fine-structure constant, alpha, are predicted in non-Standard models aimed to explain the nature of dark energy. Among them the so-called chameleon-like…

Numerous accidental near-degeneracies exist between the $2\nu_2$ and $\nu_4$ rotation-vibration energy levels of ammonia. Transitions between these two states possess significantly enhanced sensitivity to a possible variation of the…

Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…

Atomic microwave clocks based on hyperfine transitions, such as the caesium standard, tick with a frequency that is proportional to the magnetic moment of the nucleus. This magnetic moment varies strongly between isotopes of the same atom,…

We report on new tests that improve our previous (2009-2010) estimates of the electron-to-proton mass ratio variation, mu = m_e/m_p. Subsequent observations (2011-2013) at the Effelsberg 100-m telescope of a sample of eight molecular cores…

Sensitivity coefficients to temporal variation of the fine-structure constant alpha for transitions between the fine-structure (FS) sub-levels of the ground states of C I, Si I, S I, Ti I, Fe I, N II, Fe II, O III, S III, Ar III, Fe III, Mg…

Numerical calculations of the sensitivity coefficients, Q_mu, of microwave molecular transitions in the ground torsion-rotation state of deuterated methanol (CH3OD, CD3OH, and CD3OD) to small variations in the fundamental physical constant…

We identify the molecular ion NH^+ as a potential candidate for probing variations in the fine structure constant alpha and electron-to-proton mass ratio mu. NH^+ has an anomalously low-lying excited Sigma state, being only a few hundred…