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Articles 1 - 30 of 138
Full-Text Articles in Other Astrophysics and Astronomy
Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer
Emergent De Sitter Expansion And Closed Topology From The Cosmic Fabric Model As An Open Thermodynamic System: Resolving The Negative Bulk Modulus Paradox, T G. Tenev, C B. Ward, T F. Tenev, M F. Horstemeyer
Faculty Publications and Presentations
The Cosmic Fabric Model establishes a continuum-mechanics isomorphism to General Relativity by representing physical space as an elastic three-dimensional hyperplate embedded in a four-dimensional spatial bulk. Reproducing vacuum kinematics requires a vanishing P-wave modulus, which in turn implies a negative bulk modulus—an apparent thermodynamic instability in a closed system. This paradox is resolved by recasting the framework as an open system: the instability is not pathological but instead drives cosmic expansion. In this interpretation, the observable universe is a lower-energy solid formed through continuous solidification from a higher-dimensional precursor fluid. Using multiplicative kinematics from finite-growth mechanics, the model shows that …
Phase-Resolved Measurement And Arbitrary Mode Conversion Of Structured Light, Somayeh Ghazanfarpour
Phase-Resolved Measurement And Arbitrary Mode Conversion Of Structured Light, Somayeh Ghazanfarpour
Electronic Theses and Dissertations
This dissertation presents a single-shot phase and amplitude retrieval technique based on spatial light modulator (SLM)-based digital holography. The proposed method enables accurate reconstruction of complex optical fields from a single interferogram, reducing sensitivity to environmental fluctuations and improving experimental stability compared to conventional multi-shot approaches. In addition, a programmable arbitrary mode converter is developed using SLM-based wavefront shaping. By introducing controlled astigmatism and engineering the differential Gouy phase between orthogonal components, the system enables flexible transformation between structured light modes, including Hermite–Gaussian and Laguerre–Gaussian beams. Numerical results demonstrate reliable phase recovery and efficient mode conversion, validating the performance of …
Hot Jupiter Atmospheres Through Time, Annabelle E. Niblett
Hot Jupiter Atmospheres Through Time, Annabelle E. Niblett
Physics and Astronomy Undergraduate Senior Theses
Transmission spectroscopy of hot Jupiters enables mass and atmospheric composition measurements, providing insight into population dynamics and evolution when other methods are hindered by stellar activity. To effectively plan observations and interpret transmission spectra, we must have a robust understanding of how atmospheres evolve over time. To that end, we present a suite of hot Jupiter transmission spectra models with ages ranging from 3 Myr to 11 Gyr. We incorporate the cooling and contraction of the planet, which impacts the atmospheric profile, and the evolution of the stellar UV spectrum, which moderates photodissociation and photoionization. Using PICASO, VULCAN, and FastChem …
1d Crust-Magnetosphere Coupling Model For Magnetars, Kennedy M. Jeter
1d Crust-Magnetosphere Coupling Model For Magnetars, Kennedy M. Jeter
Dissertations, Theses, and Capstone Projects
Magnetars are the most extremely magnetized objects in the universe. Their strong magnetic fields generate high-energy magnetic flares with instantaneous luminosity that can outshine their host galaxy. Previous works have explored how Hall drift in the crust affects the dynamics of magnetic field lines in the magnetosphere. This work investigates how a change in the magnetosphere, such as a flare or an outburst, can excite Hall evolution in the crust. We investigate how the twisting and untwisting of magnetic field lines in a magnetar’s magnetosphere launches Hall waves through its crust using a one-dimensional numerical model. We use the Dedalus …
What Do Black Holes Teach Us About Wigner’S Friend?, Emily Adlam
What Do Black Holes Teach Us About Wigner’S Friend?, Emily Adlam
Mathematics, Physics, and Computer Science Faculty Articles and Research
Recently, Hausmann and Renner have pointed out that several famous paradoxes relating to black holes have a similar character to various Extended Wigner’s Friend paradoxes. In this paper I consider what the connection between these things could teach us about the Wigner’s Friend scenarios. I argue that if we take the analogy between these cases seriously, the black hole paradoxes appear to favour a certain class of response to the Wigner’s Friend scenario - specifically, those which posit intrinsic relationality, rather than effective and emergent relationality, and also those which posit some kind of retrocausality.
Energy Scaling And Frequency Ratios Of Particles And Constants, Alison Christina Menzmer, Donald Chakeres, Vola Andrianarijaona
Energy Scaling And Frequency Ratios Of Particles And Constants, Alison Christina Menzmer, Donald Chakeres, Vola Andrianarijaona
Campus Research Month
We are exploring quantum aspects of various physical quantities (including Bohr radius, Rydberg constant, Planck time, and Hubble constant) and mass energies of elementary particles (including electron, neutron, and quarks). We express all physical units in an energy equivalence in Hertz, normalized to 1 Hz. Furthermore, the logarithms of these normalized energies are scaled by the logarithm of a chosen particle, which allows the generation of an Arrhenius plot exhibiting numerical structures. Our results presented in this poster show that the proton is a good candidate for an Arrhenius plot with partial fractions (1 + 1/n) and (1 - 1/n).
Measurement Of 18f(Alpha,P)21ne With The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Keilah S. Davis
Measurement Of 18f(Alpha,P)21ne With The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Keilah S. Davis
LSU Doctoral Dissertations
Certain (α,p) reactions on proton-rich nuclei are among the most important nuclear reactions occurring during Type I X-ray bursts, as well as being impactful in stellar explosions during the Asymptotic Giant Branch (AGB) phase and on accreting white dwarfs (WD). However, large uncertainties remain for reaction rates on some radioactive nuclei due to the lack of direct measurements. The Array for Nuclear Astrophysics and Structure with Exotic Nuclei (ANASEN) is a gas target and charged-particle detector designed for direct measurements of (α,p) reactions. ANASEN was redesigned with two hexagonal barrels of 100-µm-thick silicon strip surrounding the beam axis over a …
The Core-Collapse Supernovae Particle Physics Interactions, Skylar G. Butler
The Core-Collapse Supernovae Particle Physics Interactions, Skylar G. Butler
Beyond: Undergraduate Research Journal
This study investigates the role of specific particle physics interactions in simulations of core collapse supernovae, with a focus on understanding how varying levels of inclusion impact the accuracy of gravitational wave predictions and results of simulations. Different research groups often approach these simulations with varying degrees of complexity, cutting corners by omitting certain reactions or simplifying others. This project systematically evaluates the implications of these choices, comparing the particle physics interactions included, the dimensionality of the simulations, and the governing equations used. Our goal is to identify how these factors influence the precision of numerical simulations. By providing a …
Survey Of Possible Magnetic Field Sources Around The Intragroup Medium Of Ngc 2563, Edward A. Wallace, Anna Williams
Survey Of Possible Magnetic Field Sources Around The Intragroup Medium Of Ngc 2563, Edward A. Wallace, Anna Williams
Macalester Journal of Physics and Astronomy
The origin and evolution of magnetic fields in space is an ongoing mystery in astronomy. Previous work has concluded the existence of magnetic fields in galaxy clusters, and to build an evolutionary model, the motivation behind this project is to determine how these magnetic fields form. In order to answer this question, we want to search for magnetic fields in galaxy group NGC 2563. To do this, our project determines the contribution to observed rotation measures of the galaxy group that come from the Milky Way and from the sources themselves.
Dose Characterization Of Galactic Cosmic Rays In The Human Brain: A Phits-Based Study With A Segmented Anatomical Phantom, Shanice N. Manning
Dose Characterization Of Galactic Cosmic Rays In The Human Brain: A Phits-Based Study With A Segmented Anatomical Phantom, Shanice N. Manning
LSU Master's Theses
Astronauts aboard the International Space Station (ISS) are chronically exposed to a complex space radiation environment composed of galactic cosmic rays (GCR), solar particles, and Earth's trapped radiation. These high-energy particles interact with spacecraft shielding, producing secondary particles that can penetrate inside and deposit energy in sensitive tissues. Although animal studies have been useful in assessing space radiation risks, anatomical and physiological differences limit their applicability to human anatomy especially neuroanatomy. To address this gap, we developed a computational framework to model radiation dose distribution within the human brain using Monte Carlo simulations in Particle and Heavy Ion Transport code …
A Catalytic Pathway For The Formation Of Cyanobenzene In Nitrogen-Rich Environments And The Spectroscopy Of The Reactive Intermediates, Vincent J. Esposito, Silvia Alessandrini, David Dubois, Ryan Fortenberry
A Catalytic Pathway For The Formation Of Cyanobenzene In Nitrogen-Rich Environments And The Spectroscopy Of The Reactive Intermediates, Vincent J. Esposito, Silvia Alessandrini, David Dubois, Ryan Fortenberry
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The catalytic reaction of isocyanobenzene (C6H5NC) with NCN− produces cyanobenzene (C6H5NC) through various highly stable reactive intermediate species. Nitrogen-rich environments such as Titan’s atmosphere serve as favorable locations to study reaction pathways involving nitrogenated species contributing to organic growth. Formation pathways of cyanobenzene have been characterized, but none with the contribution of anions or phenyl groups. In regions with a high abundance of nitrogen anions, such as Titan’s atmosphere, reactions with species such as NCN− may play a role in the formation of cyanobenzene. Highly accurate computational methods are used …
The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark
The Search For Slow Particles And Magnetic Monopoles With Nova, John Clark
Poster Presentations
Singular magnetic poles, north or south, have been theorized to exist for hundreds of years. In the modern day, the elusive singular magnetic pole still remains undiscovered. The appearance of this particle would help confirm many Grand Unified Theories, GUTs, and revolutionize our understanding of some of the fundamental forces of the universe. Fermilab's NOvA collaboration is working on ways to screen and detect magnetic monopoles and other slow-moving particles coming from outer space alongside their main mission to study neutrinos. The aim of this work is to determine and improve the Far Detector’s efficiency at identifying slow moving particles. …
Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard
Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard
Spring Showcase for Research and Creative Inquiry
This research project focuses on the computational modeling of astrophysical systems using Femap with NX Nastran. The goal was to simulate and analyze the vibrational behavior and structural deformation of celestial bodies under different material compositions and collision conditions. Materials such as iron, granite, titanium, and models for white dwarf stars were used to investigate how varying physical properties affect the systems' dynamic responses. Both isotropic and anisotropic models were created to represent realistic astrophysical materials. Through static and modal analyses, the study explored how internal structure and material stiffness influence the reaction of celestial objects to applied forces and …
19ne Excited States In Explosive Nucleosynthesis, Khang Pham
19ne Excited States In Explosive Nucleosynthesis, Khang Pham
LSU Doctoral Dissertations
Classical novae and Type I X-ray bursts are stellar explosions that occur in binary systems, where nuclear reactions involving 19Ne play a crucial role in nucleosynthesis. In novae, the destruction of 18F via the 18F(p,alpha)15O reaction significantly affects the amount of 18F remaining in the ejecta, directly influencing the detectability of predicted 511-keV gamma rays. However, discrepancies between observed and predicted 18F abundances highlight uncertainties in the reaction rates, primarily due to unknown properties of resonances in the compound nucleus 19Ne. In Type I X-ray bursts, the 15O(alpha,gamma)19Ne reaction …
Measuring Cosmic Rays With Muon Detectors (Quarknet), Aiden Burton, Jack W. Maseberg
Measuring Cosmic Rays With Muon Detectors (Quarknet), Aiden Burton, Jack W. Maseberg
SACAD: Scholarly Activities
We report measurement of atmospheric muon particles originating from cosmic rays. Using four QuarkNet project scintillators in an unstacked geometry, we are counting muons in coincidence with each other. We are currently refurbishing a second detector apparatus and will soon be capable of measuring coincidence events for larger shower surface areas using a total of eight scintillators.
Robust Spacecraft Autonomy For Deep Space Exploration In Special Euclidean Group Se(3), Matthew Wittal
Robust Spacecraft Autonomy For Deep Space Exploration In Special Euclidean Group Se(3), Matthew Wittal
Doctoral Dissertations and Master's Theses
Over the past half-century, humanity has gained extensive experience conducting manned spaceflight near Earth. Arguably, "near Earth" could even include the Moon — the most distant destination humans have reached. However, "near" in this work primarily refers low Earth orbit (LEO). One could argue that we have not truly left Earth since the Apollo, as spacecraft in some LEOs remain subject to atmospheric drag thus emphasizing their continued connection to Earth's immediate environment. Reflecting on this, it becomes clear that humanity has largely remained bound to Earth’s immediate vicinity since the Apollo missions reached the Moon. However, that is set …
Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull
Infrared Cooling In An Anharmonic Cascade Framework: 2-Cyanoindene, The Smallest Cyano-Pah Identified In Tmc-1, Mark H. Stockett, Vincent J. Esposito, Eleanor K. Ashworth, Ugo Jacovella, James N. Bull
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Infrared (IR) cooling of polycyclic aromatic hydrocarbon (PAH) molecules is a major radiative stabilization mechanism of PAHs present in space and is the origin of the aromatic infrared bands (AIBs). Here, we report an anharmonic cascade model in a master equation framework to model IR emission rates and emission spectra of energized PAHs as a function of internal energy. The underlying (simple harmonic cascade) framework for fundamental vibrations has been developed through the modeling of cooling rates of PAH cations and other carboneaous ions measured in electrostatic ion storage ring experiments performed under “molecular cloud in a box” conditions. The …
A Sensitivity Analysis Of The Modeling Of Polycyclic Aromatic Hydrocarbon Emission In Galaxies, A. Maragkoudakis, C. Boersma, P. Temi, J. D. Bregman, L. J. Allamandola, Vincent J. Esposito, A. Ricca, E. Peeters
A Sensitivity Analysis Of The Modeling Of Polycyclic Aromatic Hydrocarbon Emission In Galaxies, A. Maragkoudakis, C. Boersma, P. Temi, J. D. Bregman, L. J. Allamandola, Vincent J. Esposito, A. Ricca, E. Peeters
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We have conducted a sensitivity analysis on the mid-infrared spectral decomposition of galaxies and the modeling of the polycyclic aromatic hydrocarbon (PAH) emission spectrum with the NASA Ames PAH Infrared Spectroscopic Database (PAHdb) to assess the variance on the average galaxy PAH population properties under a grid of different modeling parameters. We find that the short-low and short-low+long-low Spitzer-IRS decomposition with PAHFIT provides consistent modeling and recovery of the 5–15 μm PAH emission spectrum. For PAHdb modeling, application of a redshift to the calculated spectra to account for anharmonic effects introduces a 15%–20% variance on the derived parameters, while its …
Photolysis And Sublimation Chemistry Of Ammonium Cyanide With Relevance To Cometary Environments, O. H. Wilkins, K. M. Yocum, Vincent J. Esposito, E. Harel, S. N. Milam, P. A. Gerakines
Photolysis And Sublimation Chemistry Of Ammonium Cyanide With Relevance To Cometary Environments, O. H. Wilkins, K. M. Yocum, Vincent J. Esposito, E. Harel, S. N. Milam, P. A. Gerakines
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Bulk nitrogen is depleted in solar system objects, including the terrestrial planets, chondritic meteorites, and comets. Recently, it was suggested that cometary nitrogen may be locked up in ammonium salts—ionic solids comprising ammonia (NH3) and an acid such as hydrogen cyanide (HCN)—based on Rosetta/ROSINA data from comet 67P/Churyumov–Gerasimanko. Among the proposed salts to have been found in 67P were ammonium cyanide (NH4CN) and ammonium cyanate (NH4OCN), which were inferred from identifying HCN, cyanamide (NH2CN), and isocyanic acid (HNCO) in the mass spectrometry data collected in the coma of 67P. However, the relationship …
Three-Dimensional Spreading Of Magnetic Reconnection Between Non-Parallel Flux Ropes With A Guide Field, Regis John
Three-Dimensional Spreading Of Magnetic Reconnection Between Non-Parallel Flux Ropes With A Guide Field, Regis John
Graduate Theses, Dissertations, and Problem Reports (ETD)
Magnetic reconnection is a fundamental plasma process that facilitates the rapid conversion of magnetic energy into particle acceleration, plasma flows, and heating. It plays a central role in explosive astrophysical events such as solar flares, where vast amounts of magnetic energy are released on short time scales. A key structure in many reconnection sites is the magnetic flux rope, a column of plasma carrying current threaded by helical magnetic fields, which is frequently involved in or generated by reconnection. Understanding how reconnection unfolds in such flux rope systems is critical for interpreting both space weather phenomena and laboratory plasma dynamics. …
The Presence Of Outer Giant Planets And Their Role In Inner Planet Formation With And Without Their Influence, Mateo E. Guerra Toro
The Presence Of Outer Giant Planets And Their Role In Inner Planet Formation With And Without Their Influence, Mateo E. Guerra Toro
Graduate Theses/Dissertations
We performed dynamical simulations of the giant impact phase of planet formation to investigate the formation of inner terrestrial planets under the influence of 4 solar system-like outer giant planets. We developed a new code using the N-body simulation suite REBOUND and REBOUNDx (Rein et al. (2019) and Tamayo et al. (2019)) to simulate 2 stages of planetary formation: a residual gaseous protoplanetary disk phase and subsequent dynamical evolution after the disk photoevaporates. The initial conditions for the inner planetary embryos were taken by Morrison et al. (2020) based on a range of solid surface densities that produced Super-Earth terrestrial …
Vibrational And Electronic Spectroscopy Of 2-Cyanoindene Cations, Thomas E. Douglas-Walker, Eleanor K. Ashworth, Mark H. Stockett, Francis C. Daly, Isabelle Chambrier, Vincent J. Esposito, Marius Gerlach, Angel Zheng, Julianna Palotás, Andrew N. Cammidge, Ewen K. Campbell, Sandra BrüNken, James N. Bull
Vibrational And Electronic Spectroscopy Of 2-Cyanoindene Cations, Thomas E. Douglas-Walker, Eleanor K. Ashworth, Mark H. Stockett, Francis C. Daly, Isabelle Chambrier, Vincent J. Esposito, Marius Gerlach, Angel Zheng, Julianna Palotás, Andrew N. Cammidge, Ewen K. Campbell, Sandra BrüNken, James N. Bull
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
2-Cyanoindene is one of the few specific aromatic or polycyclic aromatic hydrocarbon (PAH) molecules positively identified in Taurus molecular cloud-1 (TMC-1), a cold, dense molecular cloud that is considered the nearest star-forming region to Earth. We report cryogenic mid-infrared (550–3200 cm–1) and visible (16,500–20,000 cm–1, over the D2 ← D0 electronic transition) spectra of 2-cyanoindene radical cations (2CNI+), measured using messenger tagging (He and Ne) photodissociation spectroscopy. The infrared spectra reveal the prominence of anharmonic couplings, particularly over the fingerprint region. There is a strong CN-stretching mode at 2177 ± 1 cm–1 (4.593 …
Battle Of The Ch Motions: Aliphatic Vs Aromatic Contributions To Astronomical Pah Emission And Exploration Of The Aliphatic, Aromatic, And Ethynyl Ch Stretches, Vincent J. Esposito, Salma Bejaoui, Brant E. Billinghurst, Christiaan Boersma, Ryan C. Fortenberry, Farid Salama
Battle Of The Ch Motions: Aliphatic Vs Aromatic Contributions To Astronomical Pah Emission And Exploration Of The Aliphatic, Aromatic, And Ethynyl Ch Stretches, Vincent J. Esposito, Salma Bejaoui, Brant E. Billinghurst, Christiaan Boersma, Ryan C. Fortenberry, Farid Salama
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Strong anharmonic coupling between vibrational states in polycyclic aromatic hydrocarbons (PAH) produces highly mixed vibrational transitions that challenge the current understanding of the nature of the astronomical mid-infrared PAH emission bands. Traditionally, PAH emission bands have been characterized as either aromatic or aliphatic, and this assignment is used to determine the fraction of aliphatic carbon in astronomical sources. In reality, each of the transitions previously utilized for such an attribution is highly mixed with contributions from both aliphatic and aromatic CH motions as well as non-CH motions such as CC stretches. High-resolution gas-phase IR absorption measurements of the spectra of …
On The Formation And Detectability Of H2Cncn And Its Progenitors, Ryan C. Fortenberry, Vincent J. Esposito
On The Formation And Detectability Of H2Cncn And Its Progenitors, Ryan C. Fortenberry, Vincent J. Esposito
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
New highly exothermic formation pathways incorporating both thermodynamic and kinetic control for the newly astronomically detected H2CNCN molecule are paired with extremely accurate quantum chemical rovibrational spectroscopic computations. The reactions between astronomically known CH2CN/CH2CCH + HNCN follow effectively identical pathways and proceed through stable intermediates and over deeply submerged transition states to form H2CNCN and HCN/HCCH coproducts. Similarly, the reaction between CHM2CN and NCN− can also form H2CNCN, although this pathway first requires the initial formation of NCN−, which is currently undetected in space, via …
Experimental Determination Of The Unusual Ch Stretch Frequency Of Protonated Fullerenes, Laura Finazzi, Vincent J. Esposito, Julianna Palotás, Jonathan Martens, Els Peeters, Jan Cami, Giel Berden, Jos Oomens
Experimental Determination Of The Unusual Ch Stretch Frequency Of Protonated Fullerenes, Laura Finazzi, Vincent J. Esposito, Julianna Palotás, Jonathan Martens, Els Peeters, Jan Cami, Giel Berden, Jos Oomens
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We report experimental values for the CH stretch frequencies of the protonated fullerenes C60H+ and C70H+. Anharmonic frequency calculations at the B3LYP/6-31G level of theory, which are independent of empirical scaling factors, reproduce the experimental values to within approximately 5 cm−1. Scaling theoretical harmonic frequencies by applying factors derived for polycyclic aromatic hydrocarbons deviate significantly from the experimentally measured frequency. We attribute this deviation to the unusual hydrocarbon structure that affects the degree of anharmonicity of the CH stretch. This result allows us to propose an original, specific scaling factor of …
Assigning The Ch Stretch Overtone Spectrum Of Benzene And Naphthalene With Extension To Anthracene And Tetracene Using 2- And 3-Quanta Anharmonic Quantum Chemical Computations, Vincent J. Esposito, Ryan C. Fortenberry, Christiaan Boersma, Louis J. Allamandola
Assigning The Ch Stretch Overtone Spectrum Of Benzene And Naphthalene With Extension To Anthracene And Tetracene Using 2- And 3-Quanta Anharmonic Quantum Chemical Computations, Vincent J. Esposito, Ryan C. Fortenberry, Christiaan Boersma, Louis J. Allamandola
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The CH stretch overtone region (5750–6300 cm−1) of benzene and naphthalene is assigned herein using anharmonic quantum chemical computations, and the trend of how this extends to larger polycyclic aromatic hydrocarbons (PAHs) is established. The assignment of all experimental bands to specific vibrational states is performed for the first time. Resonance polyads and the inclusion of 3-quanta vibrational states are both needed to compute accurate vibrational frequencies with the proper density-of-states to match the experimental band shape. Hundreds of 3-quanta states produce the observed band structure in naphthalene, anthracene, and tetracene, and this number is expected to increase …
Cn Stretches Around 4.4 Microns Dominate The Ir Absorption Spectra Of Cyanopolycyclic Aromatic Hydrocarbons, Vincent J. Esposito, Ryan C. Fortenberry, Christiaan Boersma, Alexandros Maragkoudakis, Louis J. Allamandola
Cn Stretches Around 4.4 Microns Dominate The Ir Absorption Spectra Of Cyanopolycyclic Aromatic Hydrocarbons, Vincent J. Esposito, Ryan C. Fortenberry, Christiaan Boersma, Alexandros Maragkoudakis, Louis J. Allamandola
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Anharmonic quantum chemical computations reveal a strong, narrow (width = 0.075 μm) band in the 4.3–4.5 μm region of the absorption spectra of the cyano-substituted polycyclic aromatic hydrocarbons (CN-PAHs) cyanonaphthalene, cyanoanthracene, c yanophenanthrene, and c yanopyrene. This narro w windo w with intense IR lines implies that CN-PAHs of various shapes and sizes offer little variation in both wavelength and intensity in this region. Subsequently, this band can be used as a tracer for CN-PAHs. The distinct features making up the band are assigned to mixed vibrational states consisting of the CN stretch fundamental and various combination bands, including in-plane …
The Infrared Absorption Spectrum Of Phenylacetylene And Its Deuterated Isotopologue In The Mid- To Far-Ir, Vincent J. Esposito, Pierro Ferrari, Wybren Jan Buma, Ryan C. Fortenberry, Christiaan Boersma, Alessandra Candian, Alexander G. G. M. Tielens
The Infrared Absorption Spectrum Of Phenylacetylene And Its Deuterated Isotopologue In The Mid- To Far-Ir, Vincent J. Esposito, Pierro Ferrari, Wybren Jan Buma, Ryan C. Fortenberry, Christiaan Boersma, Alessandra Candian, Alexander G. G. M. Tielens
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Anharmonicity strongly influences the absorption and emission spectra of polycyclic aromatic hydrocarbon (PAH) molecules. Here, IR–UV ion-dip spectroscopy experiments together with detailed anharmonic computations reveal the presence of fundamental, overtone, as well as 2- and 3-quanta combination band transitions in the far- and mid-infrared absorption spectra of phenylacetylene and its singly deuterated isotopologue. Strong absorption features in the 400–900 cm−1 range originate from CH(D) in-plane and out-of-plane wags and bends, as well as bending motions including the C≡C and CH bonds of the acetylene substituent and the aromatic ring. For phenylacetylene, every absorption feature is assigned either directly or …
Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum, Ryan C. Fortenberry, Vincent J. Esposito
Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum, Ryan C. Fortenberry, Vincent J. Esposito
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
With the recent radioastronomical detection of cis-trans-carbonic acid (H2CO3) in a molecular cloud toward the Galactic center, the more stable but currently unobserved cis-cis conformer is shown here to have strong IR features. While the higher-energy cis-trans-carbonic acid was detected at millimeter and centimeter wavelengths, owing to its larger dipole moment, the vibrational structure of cis-cis-carbonic acid is more amenable to its observation at micron wavelengths. Even so, both conformers have relatively large IR intensities, and some of these fall in regions not dominated by polycyclic aromatic hydrocarbons. Water features may inhibit observation …
Possible Evidences For Existence Of An Aether Medium (Or Virtual Inertia/Spin Superfluid Medium), Victor Christianto, Florentin Smarandache
Possible Evidences For Existence Of An Aether Medium (Or Virtual Inertia/Spin Superfluid Medium), Victor Christianto, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
The presentation explores the possibility of an aether medium, also referred to as a virtual inertia/spin superfluid medium, existing to explain certain physical phenomena. While the concept of an aether has been historically rejected by mainstream physics, recent findings and interpretations offer potential justifications for its reconsideration. After discussions with several physicists, notably Robert N. Boyd, PhD and others, we are convinced that aether medium does exist, or may be called virtual inertia/spin superfluid medium.