@Mat_Hunt

I'm an applied mathematician specialising in classical continuum mechanics and batteries. @mat_hunt@mathstodon.xyz

 Little Britain
hyperkahler.co.uk
Joined May 2011
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I have written a book on Lagrangian and Hamiltonian mechanics for general mathematical modelling. Take a gander and tell me where it can be improved. You can find the book here: researchgate.net/publication…
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Every British Citizen must have a statutory right to a Bank Account. Private banks may claim the right to "de-bank" someone of whom they disapprove. Perhaps that is their contractual right. However, it is not possible for a person to live normally, in the digital age, without a Bank Account and without access to their money. It is not acceptable for any law-abiding British Citizen to be "de-banked" – which amounts to an enforced exclusion from participation in modern society; a deliberate material deprivation intended to remove a person's ability to function. Private, commercial banks are unlikely to want to cooperate with this policy. Therefore, there must be established a National Public Bank where any British Citizen can set up an account – and which can be accessed via the Post Office. This will allow any British citizen to have a current account into which they can receive money, and pay out money, physically and digitally, nationally and internationally. It doesn't need to be a Bank which lends money, and it doesn't need to be in competition with the private banking system. For example, it doesn't need to pay interest on deposits. But it must be available to those British citizens who need it! And it must be forbidden by law from denying facilities to British citizens. This is a policy made necessary by the recent actions of the private banking system, and it should be promoted by all political parties as a matter of course. igv.family/post/a-right-to-a…

A Right to a Bank Account

Every British Citizen must have a statutory right to a Bank Account. Private banks may claim the right to "de-bank" someone of whom they disapprove. Perhaps that is their contractual right.However,...

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Update: two banks have refused my applications to open an account. So far I have been debanked by @LloydsBank, suspended by @Revolut (awaiting appeal outcome) and banned from @PayPal. This is the price of opposing 'israel' in occupied Britain.
Dr Rahmeh Aladwan
@doctor_rahmehOct 13
Replying to @LloydsBank
@LloydsBank refused to give me a reason for closing my accounts. The advisor could only submit a 'complaint' to request one. It can take 8 weeks. Meanwhile, I cannot pay my bills or access my money. I must wait for a cheque and find another bank. This is political persecution.
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Having an autistic daughter is hard. She had an interaction that disregulated her, and I was following her around the neighbourhood for 90 minutes.
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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
8/ This paper continues our series with Matthew Hunt, begun in 2014. I work at @KhalifaUni; my part was supported by the French National Research Agency (ANR) through the Solar Academy graduate school. Free to read: doi.org/10.1002/mma.70433
Three cards for the papers of Matthew Hunt and Denys Dutykh on waves on electrified liquids, each removing one simplification of the classical theory. The paper of 2014, Visco-potential flows in electrohydrodynamics (Physics Letters A 378, 1721–1726), brings in weak viscosity through visco-potential flows. The paper of 2021, Free surface flows in electrohydrodynamics with a constant vorticity distribution (Water Waves 3, 297–317), brings in a constant vorticity, that is a linear shear current. The paper of 2026, highlighted, Free surface waves in electrohydrodynamics with a prescribed vorticity distribution (Mathematical Methods in the Applied Sciences 49, 7068–7081), brings in vorticity varying in both directions, a vortex patch.

ALT Three cards for the papers of Matthew Hunt and Denys Dutykh on waves on electrified liquids, each removing one simplification of the classical theory. The paper of 2014, Visco-potential flows in electrohydrodynamics (Physics Letters A 378, 1721–1726), brings in weak viscosity through visco-potential flows. The paper of 2021, Free surface flows in electrohydrodynamics with a constant vorticity distribution (Water Waves 3, 297–317), brings in a constant vorticity, that is a linear shear current. The paper of 2026, highlighted, Free surface waves in electrohydrodynamics with a prescribed vorticity distribution (Mathematical Methods in the Applied Sciences 49, 7068–7081), brings in vorticity varying in both directions, a vortex patch.

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
7/ The limits, as the paper states them: long waves of small height running one way, no viscosity, an electric field treated as static, and weak vorticity, since strong vorticity would make the surface overturn. A point vortex is out of reach; a smooth patch stands in for it.
Card listing what the model keeps and what it leaves out, as the paper states it. It keeps gravity and surface tension, the electric field acting on the liquid at its surface, any prescribed vorticity provided it is weak, and long waves of small height with their nonlinearity and dispersion. It leaves out viscosity, strong vorticity (which would make the surface overturn), waves running both ways (the long-wave equation is one-way), and point vortices, for which a smooth Gaussian patch stands in; the electric field is computed as electrostatic at each instant, in the half-space above the liquid.

ALT Card listing what the model keeps and what it leaves out, as the paper states it. It keeps gravity and surface tension, the electric field acting on the liquid at its surface, any prescribed vorticity provided it is weak, and long waves of small height with their nonlinearity and dispersion. It leaves out viscosity, strong vorticity (which would make the surface overturn), waves running both ways (the long-wave equation is one-way), and point vortices, for which a smooth Gaussian patch stands in; the electric field is computed as electrostatic at each instant, in the half-space above the liquid.

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
6/ Second test: a solitary wave about half as high as the layer is deep is sent over the same patch. It crosses and comes out with its height and speed intact, while the patch keeps making its small waves, as if the two hardly noticed each other.
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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
5/ First test: a Gaussian vortex patch under a calm surface. A dip forms right above the patch, and a train of waves runs away from it, the longest waves in front. The picture shows the surface every 10 time units, from the bottom up.
5/ First test: a Gaussian vortex patch under a calm surface. A dip forms right above the patch, and a train of waves runs away from it, the longest waves in front. The picture shows the surface every 10 time units, from the bottom up.

ALT 5/ First test: a Gaussian vortex patch under a calm surface. A dip forms right above the patch, and a train of waves runs away from it, the longest waves in front. The picture shows the surface every 10 time units, from the bottom up.

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
4/ The electric field pulls on the liquid only at its surface. For long waves of small height, the surface obeys a Benjamin equation (Korteweg–de Vries with a nonlocal electric term), and the vortex patch enters as a forcing, through integrals of its vorticity across the depth.
Card: for long waves of small height, the elevation η(x, t) of the surface obeys a forced Benjamin equation, η_t + (1 + 3η/2) η_x + κ η_xxx − γ H[η_xx] = F_ω(x). Its terms are labelled travel and steepening; gravity and surface tension (κ depends on the Bond number B); the pull of the electric field (γ depends on the electric Froude number F_E, and H is the Hilbert transform, through which each point of the surface feels the field at every other point); and the vortex patch, whose forcing F_ω is made of integrals of ∂ω/∂x across the depth.

ALT Card: for long waves of small height, the elevation η(x, t) of the surface obeys a forced Benjamin equation, η_t + (1 + 3η/2) η_x + κ η_xxx − γ H[η_xx] = F_ω(x). Its terms are labelled travel and steepening; gravity and surface tension (κ depends on the Bond number B); the pull of the electric field (γ depends on the electric Froude number F_E, and H is the Hilbert transform, through which each point of the surface feels the field at every other point); and the vortex patch, whose forcing F_ω is made of integrals of ∂ω/∂x across the depth.

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
3/ Rotation in a liquid is measured by its vorticity. Our earlier work dealt with vorticity that is constant or changes with depth only. Here it varies in both directions: the vertical velocity obeys a Poisson equation whose source is the horizontal derivative of the vorticity.
Left: the vorticity of the vortex patch used in the simulations, across the whole layer from the bottom to the free surface, centred at x0 = 0 and y0 = −0.4 depths; it is positive above the centre and negative below it, and fades within about three depths along the layer. Right: in the liquid, ∂²v/∂x² + ∂²v/∂y² = ∂ω/∂x for the vertical velocity v, with v = 0 on the bottom, so that any prescribed vorticity ω(t, x, y) can be handled without a stream function; below, the formula of the patch, ω = ω0 (y − y0) exp(−σ1 (x − x0)²/2 − σ2 (y − y0)²/2).

ALT Left: the vorticity of the vortex patch used in the simulations, across the whole layer from the bottom to the free surface, centred at x0 = 0 and y0 = −0.4 depths; it is positive above the centre and negative below it, and fades within about three depths along the layer. Right: in the liquid, ∂²v/∂x² + ∂²v/∂y² = ∂ω/∂x for the vertical velocity v, with v = 0 on the bottom, so that any prescribed vorticity ω(t, x, y) can be handled without a stream function; below, the formula of the patch, ω = ω0 (y − y0) exp(−σ1 (x − x0)²/2 − σ2 (y − y0)²/2).

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
2/ The setting: a layer of liquid that conducts electricity, on a flat bottom, under a vertical electric field. Such layers matter for coating electronics, optical devices and medical implants, and for electrospray. Their waves are usually studied as if the liquid did not rotate.
Sketch of the setting. A layer of liquid that conducts electricity, of depth h, lies on a flat solid bottom, with gravity g pointing down. A solitary wave of height η(x, t) travels to the right at speed c. Above the liquid, the field lines of a vertical electric field of strength E0 leave the surface at right angles and crowd above the crest. Inside the liquid sits a vortex patch with vorticity ω(x, y), positive (turning anticlockwise) in its upper half and negative (turning clockwise) in its lower half.

ALT Sketch of the setting. A layer of liquid that conducts electricity, of depth h, lies on a flat solid bottom, with gravity g pointing down. A solitary wave of height η(x, t) travels to the right at speed c. Above the liquid, the field lines of a vertical electric field of strength E0 leave the surface at right angles and crowd above the crest. Inside the liquid sits a vortex patch with vorticity ω(x, y), positive (turning anticlockwise) in its upper half and negative (turning clockwise) in its lower half.

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Dr Mat Hunt retweeted
Dr. Denys Dutykh
@ddutykhOct 8
Can a solitary wave cross a patch of rotating liquid and emerge unchanged? With Matthew Hunt we studied waves on a conducting liquid under an electric field, when the liquid carries vorticity. Mathematical Methods in the Applied Sciences, 2026 (@WileyGlobal) 🧵 #FluidDynamics
Banner of the journal Mathematical Methods in the Applied Sciences (Wiley), volume 49, issue 7, pages 7068 to 7081, 2026, open access: the research article "Free surface waves in electrohydrodynamics with a prescribed vorticity distribution" by M. J. Hunt and D. Dutykh, beside one of its figures, the surface above a vortex patch at the final time and its evolution in space and time, with a narrow dip above the patch and a train of waves running to the right. DOI 10.1002/mma.70433.

ALT Banner of the journal Mathematical Methods in the Applied Sciences (Wiley), volume 49, issue 7, pages 7068 to 7081, 2026, open access: the research article "Free surface waves in electrohydrodynamics with a prescribed vorticity distribution" by M. J. Hunt and D. Dutykh, beside one of its figures, the surface above a vortex patch at the final time and its evolution in space and time, with a narrow dip above the patch and a train of waves running to the right. DOI 10.1002/mma.70433.

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There has been a scam ad going around about a highland cow advent calendar. I uploaded the video to ChatGPT to ask if it could extract a 3D printer file for all 24 cows, and it did. AI has come so far...
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This video is AI. In reality, they're just 2D.
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I have an initial problem. So we'll see how it goes.
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I'm off to see a potential client this afternoon. Hopefully I can help him out with some reduced order modelling. We'll see.
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I managed to get ChatGPT to write code to produce this beautiful maths. This is free-surface electrohydrodynamics. I'm also trying to get asymmetric waves, but this is proving problematic.
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Dr Mat Hunt retweeted
Bushra Shaikh
@Bushra1ShaikhSep 23
If you've lived in England your entire life, were born in England, consider it your home and still do not feel a sense of belonging to the English national identity then there is a serious problem.
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I cannot more profoundly disagree. The mathematicians complaining about AI in math are, by and large, not the Einsteins, Atiyahs, and Diracs. They are closer to the modern Fermis, Bethes, Paulis. Some of us are excited by this!! We don’t want Pauli’s mean girl nastiness. We don’t care all that much that Bethe can think and compute faster than us. I mean it’s cool. It’s amazing that Fermi doesn’t drop a minus sign over many pages….but it’s not THAT cool. And Pauli inhibits more innovation than he sharpens the thinking of others. Every single person above I revere as a researcher. But not as a leader or referee or an elder. AI is doing a great job of scaring all the right people in math and Physics. All the people who thought “Ya know, things work pretty darn well, more or less.” I really want to emphasize: math ain’t over. AI is at last pointing what I have been talking about for 40 years: there is a LEADERSHIP *crisis* in Physics… and to a lesser extent mathematics. It is a giant mistake to listen too much to those howling most loudly. What was bad for Fauci and Collins was good for virology and good for science. What is bad for many of our leaders in Physics is Essential for Physics. Less true…but still true…for many of our top mathematicians. AI is great for the leadership crisis. For the first time: everyone outside can see what I have not found any way to communicate. Top people in science also hold back science. That may be confusing. But you are seeing it now.
Prakash
@8teAPiSep 23
I see why Tao is so sad. The era of Einstein and Feynman is over for math. It’s now the era of the 1,000 person Higgs boson team. Every mathematician now drifts towards engineering.
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Dr Mat Hunt retweeted
James Timpson
@JamesTCobblerSep 22
You can tell Ozempic and Mounjaro are popular…in our Timpson shops we have seen a 680% increase in the number of free holes in customers belts we’ve been doing this year.
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