# Post List

## Physics posts

• February 24, 2017
• 11:06 AM
• 93 views

# What if black holes were not... holes? A Los Alamos physicist explains his alternative theory behind these mysterious objects.

© Elena E. GiorgiThe concept of a “black hole” — a celestial body so dense and massive that not even light can escape its gravitational field — dates back to the 18th century, with the theoretical work of Pierre-Simon Laplace and John Michell. But it wasn’t until the early 20th century that these mysterious dark objects were first described mathematically by German physicist Karl Schwarzschild. Schwarzschild’s work predicted the existence of a finite distance around the black hole (........ Read more »

Mazur, P., & Mottola, E. (2004) Gravitational vacuum condensate stars. Proceedings of the National Academy of Sciences, 101(26), 9545-9550. DOI: 10.1073/pnas.0402717101

Emil Mottola. (2010) New Horizons in Gravity: The Trace Anomaly, Dark Energy and Condensate Stars. Acta Physica Polonica B (2010) Vol.41, iss.9, p.2031-2162. arXiv: 1008.5006v1

• February 14, 2017
• 07:02 AM
• 166 views

# Large-scale simulations of Langmuir Wave Distributions Induced by Electron Beams by H. Reid and E. Kontar

Langmuir waves that generate type III radio bursts are excited by high-energy electron beams streaming out from the corona through interplanetary space. Despite a smooth temporal distribution of electrons, the Langmuir waves are measured to occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density (e.g. Smith and Sime 1979, Melrose et al 1986). But how do fluctuations in the background plasma shape the [...]... Read more »

• January 31, 2017
• 07:06 AM
• 445 views

# Emission of radiation by plasmas with counter-streaming electron beams by L. F. Ziebell et al.*

The phenomena of emission of radiation by the Sun, which are known as type II and type III solar radio bursts, have been known and investigated for more than sixty years. The bursts of radiation occur at a frequency corresponding to the plasma frequency at the source region, and harmonics [...]... Read more »

Ziebell, L., Petruzzellis, L., Yoon, P., Gaelzer, R., & Pavan, J. (2016) PLASMA EMISSION BY COUNTER-STREAMING ELECTRON BEAMS. The Astrophysical Journal, 818(1), 61. DOI: 10.3847/0004-637X/818/1/61

• January 17, 2017
• 07:03 AM
• 232 views

# Simultaneous near-Sun observations of a moving type IV radio burst and the associated white-light CME by K. Hariharan et al.*

Quasi-continuum radio emissions of duration ~10-60 min that occur along with flares and coronal mass ejections (CMEs) in the solar atmosphere are termed as type IV bursts. The bursts are non-thermal in nature and can be classified into two categories, i.e. moving type IV (type IVm) bursts and stationary type [...]... Read more »

• January 3, 2017
• 07:01 AM
• 250 views

# Observation of quasi-periodic solar radio bursts associated with propagating fast-mode waves by C. R. Goddard et al.*

Flaring activity on the Sun triggers waves and oscillations in the solar corona. The study of these waves and oscillations allows comparisons to magnetohydrodynamic (MHD) theory and modelling to be made, and seismological inversions based on this comparison allow local plasma parameters to be measured indirectly (e.g. De Moortel & [...]... Read more »

• December 30, 2016
• 12:20 PM
• 264 views

# Yang-Mills theory paper gets published!

Exact solutions of quantum field theories are very rare and, normally, refer to toy models and pathological cases. Quite recently, I put on arxiv a pair of papers presenting exact solutions both of the Higgs sector of the Standard Model and the Yang-Mills theory made just of gluons. The former appeared a few month ago […]... Read more »

Marco Frasca. (2015) A theorem on the Higgs sector of the Standard Model. Eur. Phys. J. Plus (2016) 131: 199. arXiv: 1504.02299v3

Marco Frasca. (2015) Quantum Yang-Mills field theory. arXiv. arXiv: 1509.05292v1

Carl M. Bender, Kimball A. Milton, & Van M. Savage. (1999) Solution of Schwinger-Dyson Equations for ${\cal PT}$-Symmetric Quantum Field Theory. Phys.Rev.D62:085001,2000. arXiv: hep-th/9907045v1

• December 27, 2016
• 02:04 PM
• 419 views

# Why we have not met Aliens yet?

A huge of number of people keeps on thinking about the existence of some other intelligent beings in the universe but still we have not met any aliens. Why?

Earth is rare

Earth is special planet

One of the reasons that we have not met aliens is that Earth is rare and there is nothing just like Earth in the universe. In this regard, Paleontologist Peter Ward and astronomer Donald Brownlee presented the Rare Earth Hypothesis about 17 years ago.

According to the Rare Earth Hypothesis, t........ Read more »

Heller, R., & Armstrong, J. (2014) Superhabitable Worlds. Astrobiology, 14(1), 50-66. DOI: 10.1089/ast.2013.1088

• December 20, 2016
• 07:02 AM
• 330 views

# Diagnosing the Source Region of a Solar Burst on 26 September 2011 by Using Microwave Type-III Pairs by Tan B. L. et al.*

Accelerated electron beams are believed to be responsible for both hard X-ray (HXR) and strong coherent radio emission during solar flares. However, so far the location of the electron acceleration and its physical parameters are poorly known. The solar microwave Type-III pair burst is possibly the most sensitive signature of [...]... Read more »

• December 13, 2016
• 08:23 AM
• 359 views

# Acceleration of electrons in the solar wind by Langmuir waves produced by a decay cascade by Catherine Krafft and Alexander Volokitin

It was recently reported that a significant part of the Langmuir waveforms observed by the STEREO satellite (Graham and Cairns, 2013) during type III solar radio bursts are likely consistent with the occurrence of electrostatic decay instabilities, when a Langmuir wave $$\mathcal{L}$$ resonantly interacts with another Langmuir wave $$\mathcal{L}^{\prime}$$ and [...]... Read more »

• December 9, 2016
• 07:18 PM
• 365 views

# The Most Interesting Stellar System Of All?

Researchers at the Carnegie Institution of Washington re-examined the Kepler data and determined that it had also been steadily dimming over the course of those four years, on top of its sporadic dips in brightness. For 1,000 days, the rate of dimming observed was constant; then, for 200 days after, its dimming rate suddenly increased by some order of magnitude; finally, for the remaining 200 days, its brightness had remained largely unchanged.... Read more »

Boyajian, T., LaCourse, D., Rappaport, S., & et al. (2016) Planet Hunters IX. KIC 8462852 – where's the flux?. Monthly Notices of the Royal Astronomical Society, 457(4), 3988-4004. DOI: 10.1093/mnras/stw218

Montet, B., & Simon, J. (2016) KIC 8462852 FADED THROUGHOUT THE MISSION . The Astrophysical Journal, 830(2). DOI: 10.3847/2041-8205/830/2/L39

• December 6, 2016
• 02:29 PM
• 369 views

# Fun With Non-Ionizing Radiation

Does non-ionizing radiation pose a health risk? Everyone knows that ionizing radiation, like gamma rays, can cause cancer by damaging DNA. But the scientific consensus is that there is no such risk from non-ionizing radiation such as radiowaves or Wi-Fi.

Yet according to a remarkable new paper from Magda Havas, the risk is real: it's called When theory and observation collide: Can non-ionizing radiation cause cancer?

There are a few remarkable things about this paper but chief among th... Read more »

• December 6, 2016
• 07:08 AM
• 285 views

# Source regions of the type II radio burst observed during a CME–CME interaction on 2013 May 22 by P. Mäkelä et al.*

Occasionally the Sun ejects a pair of magnetized plasma clouds, called coronal mass ejections (CMEs), roughly into the same propagation direction in closely timed sequence. If the second CME is faster than the first one, the CMEs could either just slip through each other or they could collide and interact, [...]... Read more »

• November 29, 2016
• 07:02 AM
• 329 views

# Simultaneous Submillimeter and Hard X-Ray Intermittent Processes during Flares by Guillermo Giménez de Castro et al.*

Intermittency is a disruptive characteristic of a process, which can be associated, in many cases, with a sudden energy release. Intermittency is a key characteristic of flares that should become evident in the flux time evolution at many different wavelengths. We investigate the similarities and differences of the intermittency during [...]... Read more »

• November 22, 2016
• 07:03 AM
• 356 views

# Energetic electrons generated during solar flares by Gottfried Mann

The Sun is an active star. It manifests not only in everybody’s well-known Sun spots with the related 11-year cycle. This activity manifests not only as the well-known sun spot phenomenon with a related 11-year cycle, but also in flares, coronal mass ejections (CMEs), and solar energetic particle (SEP) events. Thus, [...]... Read more »

Gottfried Mann. (2016) Energetic electrons generated during solar flares. Journal of Plasma Physics. info:/

• November 15, 2016
• 07:05 AM
• 330 views

# Solar Type III Radio Bursts: Directivity Characteristics by G. Thejappa and R. J. MacDowall

Type III radio bursts are a group of fast drifting radio emissions associated with solar flares [see also previous CESRA highlights on type III bursts here and here]. These radio emissions are believed to be excited at the fundamental and second harmonic of the electron plasma frequency, by the electron beam excited Langmuir waves [...]... Read more »

G. Thejappa and R. J. MacDowall. (2015) Solar Type III Radio Bursts: Directivity Characteristics . Journal of Physics: Conference Series. info:/

• November 1, 2016
• 09:01 AM
• 415 views

# Multiwavelength study of 20 jets that emanate from the periphery of active regions by Sargam M. Mulay et al.*

Solar jets are transient phenomena observed in the solar atmosphere. They appear as sharp-edged, impulsive, and collimated flows of plasma that move outwards with a bright spot at the footpoint, which forms an ‘inverted-Y’ topology of magnetic field lines. They are observed throughout the atmosphere i.e. in the photosphere (Hα, Ca II K [...]... Read more »

Mulay et al. (2006) Multiwavelength study of 20 jets that emanate from the periphery of active regions. Astronomy . info:/

• October 18, 2016
• 09:02 AM
• 446 views

# Decameter type III bursts with changing frequency drift-rate signs by V. Melnik et al.*

We discuss properties of type III bursts that change the sign of their drift rate from negative to positive and vice versa. Moreover, these bursts may change the sign of their drift rates more than once. These particular type III bursts were observed simultaneously by the radio telescopes UTR-2, URAN-2, [...]... Read more »

V. Melnik et al. (2015) Decameter type III bursts with changing frequency drift-rate signs . Solar Physics. info:/

• October 4, 2016
• 09:05 AM
• 448 views

# Propagation of Coronal Mass Ejections: Aerodynamic Drag by Nishtha Sachdeva and Prasad Subramanian

Coronal Mass Ejections (CMEs) are hot, massive blobs of plasma and magnetic fields that erupt from the Sun, and are sometimes Earth-directed. Depending on their speed and mass these transients can strongly effect the space weather, causing geomagnetic storms and damage to space bound technologies. It is therefore imperative to [...]... Read more »

Sachdeva, N., Subramanian, P., Colaninno, R., et al.,. (2015) Propagation of Coronal Mass Ejections: Aerodynamic Drag. Astrophysical Journal, 158. info:/

• October 3, 2016
• 12:08 PM
• 475 views

# The 7 Most Interesting Extrasolar Systems.

Beyond the well-known Solar System, there is an immensity of other unique systems... Read more »

Johanna K. Teske, Stephen A. Shectman, Steve S. Vogt, Matías Díaz, R. Paul Butler, Jeffrey D. Crane, Ian B. Thompson, & Pamela Arriagada. (2016) The Magellan PFS Planet Search Program: Radial Velocity and Stellar Abundance Analyses of the 360 AU, Metal-Poor Binary "Twins" HD 133131A . Astronomical Journal,. arXiv: 1608.06216v2

Orosz, J., Welsh, W., Carter, J., Fabrycky, D., Cochran, W., Endl, M., Ford, E., Haghighipour, N., MacQueen, P., Mazeh, T.... (2012) Kepler-47: A Transiting Circumbinary Multiplanet System. Science, 337(6101), 1511-1514. DOI: 10.1126/science.1228380

R. Di Stefano, & A. Ray. (2016) Globular Clusters as Cradles of Life and Advanced Civilizations. ASTROPHYSICAL JOURNAL , 827(1). arXiv: 1601.03455v1

Marcelo Tucci Maia, Jorge Melendez, & Ivan Ramirez. (2014) High precision abundances in the 16 Cyg binary system: a signature of the rocky core in the giant planet. ASTROPHYSICAL JOURNAL LETTERS , 790(2). arXiv: 1407.4132v1

Anglada-Escudé, G., Amado, P., Barnes, J., Berdiñas, Z., Butler, R., Coleman, G., de la Cueva, I., Dreizler, S., Endl, M., Giesers, B.... (2016) A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature, 536(7617), 437-440. DOI: 10.1038/nature19106

Borucki, W., Agol, E., Fressin, F., Kaltenegger, L., Rowe, J., Isaacson, H., Fischer, D., Batalha, N., Lissauer, J., Marcy, G.... (2013) Kepler-62: A Five-Planet System with Planets of 1.4 and 1.6 Earth Radii in the Habitable Zone. Science, 340(6132), 587-590. DOI: 10.1126/science.1234702

Stephen R. Kane, & Dawn M. Gelino. (2014) On the Inclination and Habitability of the HD 10180 System. ASTROPHYSICAL JOURNAL, 792(2). arXiv: 1408.4150v1

• September 30, 2016
• 04:33 PM
• 284 views

# Detecting atmospheric pollutants with laser filamentation

A method for remotely detecting pollutants and other chemicals in the atmosphere has been demonstrated by physicists at the Massachusetts Institute of Technology, using laser-generated jets of plasma. Their laboratory experiments could pave the way to instruments used to monitor pollution levels high in the atmosphere, or for detecting hazardous biochemicals in an industrial process from a safe stand-off distance.... Read more »

Liang, H., Weerawarne, D., Krogen, P., Grynko, R., Lai, C., Shim, B., Kärtner, F., & Hong, K. (2016) Mid-infrared laser filaments in air at a kilohertz repetition rate. Optica, 3(7), 678. DOI: 10.1364/OPTICA.3.000678